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SELIMCAN DEDA SMART BATTERY POWER MANAGEMENT UNIT

1. eusssss 24 3 4 Starting up the MAX11068 EV Kit ana eene ener 25 3 4 1 MAX11068 EVKit SMBus Ladder eene nenne 27 esM VP cL o pora EF A Y NYD 28 3 6 Comparison of Selected BMS Boards eee Idee eie erase ae dB NL SS 30 4 Power Management System Design aaa vana aaa akan 32 5 Programming of Power Management Unit eese 36 5 Flowchart of Programming of PMU essere enne enne 36 iv 3 2 Jaya Libraries i5 aia b i e i i ede eed 38 5 3 State of Charge SoC Calculation PUncHOn ok eu eee rodea ERE aee ea ER Te eh 38 6 Results and DISGUSSIOD alise eite ddon dd etia ti dead ddad ated iM oisi dela 39 6d Graphical User Interface sso eco bb esa E O 39 6 2 Cell Measurement Results ce etr Ua e a Ue dte orta ee YG ue dessus 40 G2 JGUTCGhart Resullsu ipte o cete adi en ab tail 42 6 2 3 ExcelResultS nai Re ie d ed Ee doo 44 6 3 Load Dist hari Curve iso ies a Y YN ate 45 Te Conclusions sutor opio celo tees i etal ale eet A 49 8 Continuation Design of Work ado eee p eite ues tae e ee Okt Sat seal ue aUe ORE aj 50 References gt e odala odi dt FY TNS dbi a dio ika YN peut 32 Appendix 1 MAX11068 EVKit Cell Configuration Headers and Switch 57 Appendix 2 MAX11068 EVKit Cell Connection Switches and Headers 60 Appendix 3 Discharging Enersys Cyclon Batteries
2. seen 61 Appendix 4 Timing of Parameter Updates During the Relaxation Mode for State of Health Estima On coisa ok FFO dodaj dodi FN espe dl dida OS 62 LIST OF FIGURES Figure 1 General PMU Block Diagram bt RGAE 3 Figure 2 Some examples of application areas of PMU sse 3 Figure 3 Power in MW vs time Wikipedia 2009 sese 4 Figure 4 Cost vs Increasing Renewable Energy Penetration Begovic 2012 5 Figure 5 Charge Current vs Charging Time for three different current limits Linden et al 2002 a a e e o m pr na 8 Figure 6 Hyperion AC DC EOS0606iAD C battery charger Hyperion 2013 9 Figure 7 Enersys Cyclon Battery Open Circuit Voltage vs State of Charge Enersys Cyclon 200 Go decease tu nere as nei A EE A sj i dd I2 Figure 8 PC bus bit transmission NXP Semiconductors 2012 17 Figure 9 START and STOP conditions NXP Semiconductors 2012 17 Figure 10 Complete Data Transfer NXP Semiconductors 2012 sss 18 Figure 11 Functional Communication Initialization Sequence Diagram of MAX11068 Maxim Integrated 20 10 6o coe t aban fr tutt gt eu de gei ae Piave videt odo een Potes dug 21 Figure 12 Functional Block Diagram of MAX 11068 Maxim Integrated 2010 22 Figure 13 MAX11068 EV Kit Maxim Integrated esee 23 Figure 14 MAX11068 EVKit SMBus Ladder when Board A is fir
3. 36 5 PROGRAMMING OF POWER MANAGEMENT UNIT NetBeans IDE is used for Smart Battery Power Management Unit project NetBeans IDE is written in one of most widely used programming language Java Net Beans 2013 A Java based software program NetBeans IDE is used in this project for the voltage measurement and display of each battery cell voltage including maximum and minimum voltages of cells of the battery pack and helps to establish a connection with user Programming of MAX11068 evaluation kit EVKit is the major part of Smart Battery Power Management Unit PMU project The Programming of Smart Battery PMU project is mainly divided into three parts which are Serial Communication graphical user interface GUI and the main classes 5 1 Flowchart of Programming of PMU At the beginning the GUI is initialized After that universal serial bus USB to Serial Communication is initialized via getting port identifiers and searching a serial communication COM port element If port enumeration contains more elements it returns the next element of this enumeration If COM port is not found the software returns error result On the other hand if COM port is found then serial port and USB to Serial input output I O streams are opened the event listeners are added and the function checks while the input data is stated as sent and available When the USB to Serial Communication is completed the voltages are acguired The acguired voltages
4. 45 The labels that show SoC results of 24 cells follow the labels that show the voltage results of 24 cells 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 80 00 Figure 31 Cell SoC and date amp time displayed in Excel sheet 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 can be obtained 6 3 80 00 80 00 85 00 80 00 80 00 80 00 85 00 85 00 85 00 80 00 80 00 85 00 85 00 80 00 85 00 90 00 85 00 85 00 85 00 85 00 85 00 85 00 90 00 85 00 85 00 85 00 85 00 85 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 85 00 85 00 90 00 85 00 85 00 85 00 85 00 85 00 90 00 85 00 85 00 90 00 85 00 Load Discharging Curve 75 00 75 00 75 00 75 00 75 00 75 00 75 00 75 00 75 00 75 00 75 00 70 00 75 00 75 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 75 00 75 00 80 00 75 00 75 00 75 00 75 00 75 00 75 00 80 00 80 00 75 00 80 00 75 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 90 00 95 00 95
5. 20 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 Consequently MAX11068 gets functional after any reset event In Figure 11 the complete functional PC SMBus ladder communication initialization sequence diagram of MAX11068 is shown The SMBus ladder modules are set for operation after they are regulated for communication MAX11068 NACK HELLOALL I COMMUNICATION ERROR ACK NACK ROLLCALL m COMMUNICATION ERROR ACK SLAVE DATA IS RECEIVED UNTIL CONSECUTIVE 0xFF BYTES THEN SLAVES ARE NACKED CALCULATION OF NUMBER OF DEVICES IS CALCULATION OF NO NUMBER OF DEVICES SYSTEM ERROR CORRECT wes NACK SETLASTADDRESS I COMMUNICATION ERROR pe STATUS REGISTER BITS ARE CLEARED COMMUNICATION IS INITIALIZED Figure 11 Functional Communication Initialization Sequence Diagram of MAX11068 Maxim Integrated 2010 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 3 2 MAX11068 The MAX11068 integrated battery sensor is used for managing the lead acid batteries in this MSc Thesis The BMS topology is master slave architecture in MAX11068 The MAX11068 can measure the voltage of up to 12 cells and has two auxiliary ports which can be used with thermistors for temperature measurements Moreover the MAX11068 evaluation kit EVKit
6. At below three main steps for recharging Lead Acid batteries are given Reddy 2011 1 At the beginning of recharging process the charging current should not generate an average battery cell voltage which is greater than 2 4V gassing threshold For cyclic applications the charging current should not generate an average battery cell voltage which is greater than 2 5V Enersys Cyclon 2008 2 The charging current should be managed so that the cell voltage is kept lower than 2 4V for cyclic applications cell voltage is kept lower than 2 5V during the recharging process and till 100 of previous discharging capacity is achieved 3 The current starts to decay to charge finishing rate when the battery begins to saturate The recharging process should be ended up at a constant current which is not more than that charge finishing rate There are three main methods for recharging batteries Constant Current CC charging method Constant Voltage CV charging method or Constant Current Constant Voltage CC CV charging method can be used depending on certain conditions First of all since current adjustment is required if the charging current is not restrained at a low level the recharging duration becomes longer Therefore the CC charging method is not broadly used for recharging lead acid batteries On the other hand for charging Enersys Cyclon Lead Acid batteries the CC CV charging can be used because it applies single constant current vol
7. Test_Time s Qmax Update Because dV dt lt 4 uV s Voltage V
8. The core Java libraries are used for developing Smart Battery PMU which are listed in Table 18 Table 18 The used core Java libraries The core Java libraries java awt java io java nio java text java util javafx javax swing jxl The java awt is utilized for generating user interfaces and graphics Moreover java io is made use of providing system input and output via data streams and serialization java nio is used for defining buffers that are containers of data java text is used for processing texts and numbers java util is utilized for handling events date and time In addition javafx is made use of ensuring the modern looking user interface javax swing is used on top of the java awt Furthermore jx is utilized for writing reading and updating Microsoft Excel sheets dynamically 5 3 State of Charge SoC Calculation Function The each battery cell voltage and SoC is set to 0 in code at the beginning of measurement The measurements are being updated by first and individual Battery Management System BMS cell voltages are acquired and added together Following this addition the total voltages are divided to 24 As a consequence total battery voltage is calculated After that SoC calculation method is called and those BMS cell voltages are placed to that method Consequently SoC of each cell is calculated Then all individual cell SoCs are added an
9. UE r 3 2 3 29 J108 1 gt 1 o Zo N kose P103 20 4 1 1 1 i i L U coal gt Sw22 0 i co s 54 wi22 0 i i U U 7 1 i nosi o PHLU 03 21 2103 22 U i I U 1 L U cena D i Sw22 E i ms Ds i sw22 e i 1 E 0 i J8 2 o a 1 403 23 p3 235 108 12 4 e _ro a 103 23 p103 23 i 1 i 1 i D i i c2 A 54 i Sw22 F i 1 e28 5 SW122 F f i 1 i i L I U JB 13 o 1 463 25 P3 2d gt i J108 13 1 bmo 4103 25 P103 28 J 1 1 i D I U 1 5w22 G 1 SW122 G i 1 D i a Ey Use ss i ey 2 4 1 1 SW22 SW122 61 APPENDIX 3 DISCHARGING ENERSYS CYCLON BATTERIES In the table below the recommended EODV with respect to the Discharge Rate is given Enersys Cyclon 2008 Discharge Rate A Minimum EODV cell V 0 05C 9 1 75 0 1Cio 1 7 0 2C io 1 67 0 4C 19 1 65 Cio 1 6 2Cio 1 55 4Ci1o 1 5 APPENDIX 4 TIMING OF PARAMETER UPDATES 62 DURING THE RELAXATION MODE FOR STATE OF HEALTH ESTIMATION During the relaxation mode the timing of DoDo and Qmax updates are given below Texas Instruments 2006 Subsequent DOD K Measurement 100 s Interval Current A 3 my ooo 4000000 00000 Sao Fo DD a 000 000 5 hr Gmax Update Because Maximal Time Exceeded 9 8 sooo
10. volume applications The KERS project requires a 48V battery which provides energy to DC DC converter and motor controller Also the DC DC converter and motor controller restore energy to 48V battery Hence this MSc Thesis can be used for the bigger KERS project as it is a 48V smart battery PMU which allows providing and restoring energy and provides an accurate voltage and SoC monitoring system 50 8 CONTINUATION DESIGN OF WORK The whole system is done by RFIC Laboratory Research Group The future BMS PMU block diagram plan is designed and illustrated in Figure 34 It will be mainly consisted of source control and load parts In this MSc Work I work in the monitoring part of the system In Figure 34 the communications between 48V 24 cell lead acid battery microcontroller Arduino and MAX11068 EVKits in control part are already done My MSc work can be improved by the block diagram given in Figure 34 BMS BLOCK DIAGRAM JUHA amp SELIM Rev 1 1 26 04 2013 SOURCE CONTROL LOAD 220V AC at LAPTOP o 48V CHARGER dA Q 3 12 24 36V 3A DCDC BOOST LTC3862 NMOS BUK654R0 75C DC1286A A 48V 3A NMOS 48V LOT GND BUK654R0 Lead Acid 75C Battery E BMS 2 sen c Control 48V EVKIT 0 1A DCDC BUCK LTC3890 DC1804A 19 12V GATE1 GATE LDO GATE GATE2 DRIVER 1 LM7810 DRIVER 2 IR2117 OPTIONAL IR2117 10V 5V uc 5V o Uno Figure 34 Future BMS PMU Bl
11. 00 95 00 95 00 95 00 95 00 95 00 95 00 95 00 95 00 95 00 95 00 95 00 95 00 2013 12 17 18 25 51 2013 12 17 18 25 52 2013 12 17 18 25 53 2013 12 17 18 25 54 2013 12 17 18 25 55 2013 12 17 18 25 56 2013 12 17 18 25 57 2013 12 17 18 25 58 2013 12 17 18 25 59 2013 12 17 18 26 00 2013 12 17 18 26 01 2013 12 17 18 26 02 2013 12 17 18 26 03 2013 12 17 18 26 04 From the Figure 31 the changes of each cell SoC with respect to the date amp time The load discharging curves help to observe the health of battery cells The battery cell discharge performance depends on the load and how they are used In Figure 32 the behavior of total battery voltage with respect to time when the load is connected is illustrated The current through the load is 0 74A at the beginning of discharging process It is dropped to 0 72A at the end of the discharging process Therefore there is a 0 02A difference between the beginning and end of discharging process 6 RESULTS AND DISCUSSION 50 45 40 35 30 25 20 Total Lead Acid Battery Voltage V Total Lead Acid Battery Voltage vs Time _ 0 20 40 60 80 100 Time mins Figure 32 Total lead acid battery voltage versus time 120 46 In the Figure 32 the total battery voltage is 50 87V at the beginning After 116 minutes it is dropped to 44 8V Apart from Figure 32 in Figu
12. 20 Table 20 Comparison of GUI and multimeter lead acid battery cell measurements GUI Multimeter Cell 1 1 95 1 94 Cell 2 1 96 1 95 Cell 3 1 96 1 95 Cell 4 1 95 1 94 Cell 5 1 95 1 94 Cell 6 1 94 1 93 Cell 7 1 97 1 96 Cell 8 1 97 1 96 Cell 9 1 96 1 96 Cell 10 1 97 1 97 Cell 11 1 97 1 96 Cell 12 1 92 1 91 Cell 13 1 96 1 96 Cell 14 1 97 1 96 Cell 15 1 94 1 93 Cell 16 1 95 1 95 Cell 17 1 96 1 95 Cell 18 1 96 1 95 Cell 19 1 9 1 89 Cell 20 1 95 1 95 Cell 21 1 91 1 91 Cell 22 1 96 1 95 Cell 23 1 95 1 94 Cell 24 1 96 1 96 From Table 20 it can be concluded that the GUI shows correct results The 0 5 difference between the GUI and multimeter measurements is acceptable The difference might be caused by rounding tolerances and or cable losses 50 7 CONCLUSIONS In conclusion this MSc Thesis studies the smart battery PMU for a 48V battery pack of series connected 24 lead acid cells An alternative voltage and SoC monitoring system is proposed for current Battery Management Systems which monitors the voltages and SoCs of lead acid battery cells properly during both charging and discharging In addition the software allows users to save measurement data to utilize them whenever it is required The main goal which is set before the MSc Thesis is achieved During the MSc Thesis project at first the initial calculation
13. 2010 In the Smart Battery PMU project two MAX11068 boards boards A amp B are used They are connected via ribbon cable that placed across the jumpers J2 and J101 Furthermore the cell configuration headers J101 and J102 are given in Appendix 1 Table 14 JI Header Pinout of MAX11068 EVALUATION KIT PACK A Pin Number Net Association 1 SHDNA 3 SCLLA 5 SDALA 7 ALRMLA 9 10 11 12 CO A 13 SHDNINCA 15 17 Not Configured 19 ALRMOUTCA 2 4 6 8 GNDLA 14 16 18 20 AGNDCA 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 Table 15 J2 Header Pinout of MAX11068 EVALUATION KIT PACK A Pin Number Net Association 1 CP A 3 SCLU_A 5 SDAU_A 7 ALRMU_A 9 10 11 12 C12_A 13 CP CA 15 17 Not Configured 19 ALRMINCA 2 4 6 8 GNDUI 14 16 18 20 GNDU2 3 5 Arduino Due The Arduino Due is chosen for this MSc Thesis Arduino Due is a microcontroller board which has Atmel SAM3X8E 32 bit ARM chip Atmel on it The Arduino Due has 54 digital pins and each of them can be utilized as an input or output Nonetheless 12 of digital I O pins can be used as pulse width modulation PWM outputs They operate at 3 3V The input output I O pins can tolerate maximum 3 3V Additionally the direct current DC current for 3 3V pin is 800mA The programming port of Arduino Due is connected to an ATmegal6U2 microcontroller which ensures a virtual communication COM port A
14. 26 Table 13 J3 Header Pinout of MAX11068 EVALUATION KIT PACK A 26 Table 14 J1 Header Pinout of MAX11068 EVALUATION KIT PACK A 27 Table 15 J2 Header Pinout of MAX11068 EVALUATION KIT PACK A 28 Table 16 Pin mapping of Arduino Due that used in system eee 29 Table 17 Comparison of Different BMS Evaluation Kits esse 30 Table 18 The used core Java libraries aiu ee ce eati erben 38 Table 19 SoC 96 and SoC Icon with respect to it sese 41 Table 20 Comparison of GUI and multimeter lead acid battery cell measurements 48 vili LIST OF ABBREVIATIONS ACK ADC BMS CC CC CV COM CV DC DoD EODV EV EVKit FCC FET FWUP GND GPS GUI IC Pc VO JU KERS LDO LED LSB Max Min MOS MOSFET MSB NACK acknowledge analog to digital converter battery management system constant current constant current constant voltage communication constant voltage direct current depth of discharge end of discharge voltage electric vehicle evaluation kit full charge capacity field effect transistor faster wakeup ground global positioning system graphical user interface integrated circuit inter integrated circuit input output jumper kinetic energy recovery system low dropout regulator light emitting diode least significant bit maximum minimum metal oxide semiconductor metal oxide semicondu
15. Battery Management Systems and Save Power Too Accessed on 07 10 2013 Available at http www eetasia com STATIC PDF 201205 EEOL 2012MAY03 POW TEST AN 0 1 pdf SOURCES DOWNLOAD Rahimi Eichi H Ojha U Baronti F Chow M 2013 Battery Management System An Overview of Its Application in the Smart Grid and Electric Vehicles Industrial Electronics Magazine IEEE vol 7 no 2 Reddy T B 2011 Linden s Handbook of Batteries Fourth Edition McGraw Hill New York Tampere University of Technology RF Integrated Circuits Laboratory 2013 Mobile Stationary Big Volume Applications Accessed on 09 01 2014 Available at http www cs tut fi tlt rfasic RFCClab pdf Tanaami A Morimoto M 2009 On line Estimation of SOH for Lead Acid Battery PEDS 2009 International Conference on Power Electronics and Drive Systems Taipei Taiwan R O C Texas Instruments 2006 bg20z80 Application Book Texas Instruments 2012 Wide Range Fuel Gauge with Impedance Track for Lead Acid Batteries Accessed on 04 10 2013 Available at http www ti com lit ds slusb55a slusb55a pdf The Boston Consulting Group Inc 2010 Batteries for Electric Cars Challenges Opportunities and the Outlook to 2020 Boston MA USA Accessed on 19 04 2013 Available at http www bcg com documents file36615 pdf 56 Wang P Liang B Ye X Ko W H Cong P 2010 A Simple Novel Wireless Integrate
16. Bo Pl o I TI S BR 1 2x LALETAtUTE REVIEW o radije joS o baklja too iga raje 2 2 1 What does Battery Management System BMS mean sss 2 2 1 1 The Functions of Power Management Unit PMU vao 2 2 1 2 Application Areas of PMU 5 tene estet o eee S aae eo nose AROS 3 2 2 Cell Balancing Methods for PME a eiua nae FY edge dee t 5 23 JLead Acid Batteries uci tied da tal Geste edt dau vea ela 6 2 3 The History and Present of Lead Acid Batteries sess 6 2 32 Charging Lead Acid Batteries sis eode ie soda dan 7 2 3 2 1 Constant Current Constant Voltage Charging esessse 7 2 3 3 Comparison of Rechargeable Batteries sese 9 2 3 4 Future of eau Acid Batteries oe an Y di o 11 2 4 State of Charge SoC Calculations uestem tet 08 do FYN WG LS ada kaosa 11 ZI The SoC Calculation Methods ea dol eo set la casters Sade e 11 2 5 State of Health SoH Estimations eeavenaoaa aaa nakana kaaa Yno 13 3 System Considerations Based on MAX11068 seen 16 3 1 Inter Integrated Circuit PC Communication ees 16 3 1 1 Serial Data Line SDA and Serial Clock Line SCL 17 32 AL C Command Bist o oot eoo e tun mae aate 19 MEN S Nd PP Er 22 3 2 1 Analog to Digital Converter ADC sse 24 3 3 Jumper Switch Configurations and Cell Connections
17. On On On Off Off Off Off Off Off On On On On Off Off Off Off Off Off Off On On On Off Off Off Off Off Off Off Off On On Off Off Off Off Off Off Off Off Off On t oe e om eR o rm Off Off Off Off Off Off Off Off Off Off As 12 cells are used for each MAX11068 Evaluation Kit Pack in our Smart Battery PMU project the shunts given in Table 9 should be positioned off Moreover the cell stack voltage is ensured by cascading 12 battery cells between CO A to C12 A and CO B to C12 B nodes In addition to Table 10 for MAX11068 EVALUATION KIT PACKB header P103 has same cell connections as P3 24 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 Table 10 Header P3 Cell Connections of MAX11068 EVALUATION KIT PACKA CELL TERMINAL TERMINAL 1 P3 2 P3 4 2 P3 4 P3 6 3 P3 6 P3 8 4 P3 8 P3 10 5 P3 10 P3 12 6 P3 12 P3 14 7 P3 14 P3 16 8 P3 16 P3 18 9 P3 18 P3 20 10 P3 20 P3 22 11 P3 22 P3 24 12 P3 24 P3 26 3 4 Starting up the MAX11068 EV kit After applying at least 6 Volts across MAX11068 EVALUATION KIT PACKA and PACKA SHDNINA net should be droved high In our project we control SHDNINA by our software To do this in addition to the Table 10 the jumpers and switches should be configured as in the Table 11 according to the Maxim Integrated MAX11068 Evaluation System 2010 Table 11 Jumper Configurations of MAX1
18. T2 Tb 9T 22 16 97 Z Tb 9T pcTp 9T 9c Tp 9T C1r 9T 8c Tp 9T 3 m Battery Voltage Figure 27 Total Battery Voltage vs Time Battery Voltage vs Time Voltage V 6p 0 91 TS 90 9T 25 60 9T cs lt T 9T bS ST 9T SS 8T 9T LS T1C 9T 85 pc 9T 6S c 9T ZO T 9T 0 p 9T p0 9T p0 0p 9T 90 p 91 0 9p 9T 80 6 9T 60 75 91 60 SS 9T 0T 8S 9T TT TO ZT 3 o Figure 28 Total Battery Voltage vs Time in a different period of time From Figure 28 the total 24 cells battery voltage is approximately egual to 48V As it is discussed in section 2 4 a SoC calculation algorithm is applied to estimate SoC of battery cell voltages In a few words it is estimation However the total battery voltage is directly shown in GUI charts without any estimation or calculation Therefore it is also obtained from Figures 27 and 28 that the total battery voltage is more stable than total battery SoC 6 RESULTS AND DISCUSSION 44 In the Figure 29 the instantaneous total battery voltage SoC and status are given Battery Voltage Battery Soc Battery Status Figure 29 Instantaneous Battery Voltage SoC and Status According to the Figure 29 it can be acquired the battery is in a safe condition because the total battery SoC is more than 40 The total battery is charged 48 and its voltage is 48 74V The clock is also added to GUI so the users can observe battery voltage SoC and status at any
19. are read After reading voltages the State of Charge SoC calculation function is called Thereafter the measurements are updated in GUI When the measurements are updated then the program returns to get more voltage measurements Simultaneously when the measurements are updated in GUI the software gives users two choices which are shutting down the software or writing data to Microsoft Excel Sheet The data is written to Microsoft Excel Sheet via creating a new excel file and sheet instantiating cell objects and adding for the Excel sheet writing cell voltages SoC results measurement counter and timestamp to file from measurement registers When the data is written to Microsoft Excel sheet then the program returns to get more 5 PROGRAMMING OF POWER MANAGEMENT UNIT 37 voltage measurements The full simplified and visualized flowchart is illustrated in Figure 22 The steps that the software follows are shown in the flowchart Start d GUI initializations P j Fr Initializing USB to Serial E Communication D a h Getting voltages lt b P a Read voltages d b Calculate SoC 4 4 b Updating the measurement in GUI User shuts down the software Y a End NA Figure 22 The flowchart of programming of PMU GUI Write to Excel button y gt Microsoft Excel Writing Data to L u Sheet P 5 PROGRAMMING OF POWER MANAGEMENT UNIT 5 2 Java Libraries
20. can measure the voltage of up to hundreds of cells depending on the battery selection In Figure 12 Functional Block Diagram of MAX1 1068 is illustrated Maxim Integrated 2010 DCIN VAA REF GNDU VDDU 6V to 72V j 12C Upper ALRMU mE Regulator 25V Port POR AUXIN2 4 AUXIN1 4 DIS Select 11 0 Oscillator Ci2 C11 4 op Su Level Shift Lop Instrumen Switch Bank Control and ce tation I2iADC cas C6 Cell Equalization DT COM C4 4 3 4V 02 32 kHz ci Oscillator I ALRML SCLL SDAL SW Select SHDN 26 0 12C Lower Port GNDL VDDL GPIO0 GPIO1 GPIO2 Figure 12 Functional Block Diagram of MAX11068 Maxim Integrated 2010 In Figure 12 cell data is obtained by consecutive approximation of 12 bit analog to digital converter ADC It also enables to measure internal and external temperature The switch bank results from a high voltage multiplexer It forms switching between the cells When cells are switched the cells are measured by the 12 bit ADC and after that they are stored in internal memory All cells are measured wi
21. constant voltage of 2 45V 2 5 E E 2A 1A 0 3A Charge Current A 0 5 0 0 1 2 3 4 5 6 7 8 2 10 time h Figure 5 Charge Current vs Charging Time for three different current limits Linden et al 2002 From the Figure 5 it can be observed that the amount of time to recharge the battery is varied for different current limits The battery charging process is started with a constant current for different charging currents When the battery voltage is reached the gassing voltage threshold the charging current starts to drop The only difference between those three charging limits is the amount of time needed to recharge the battery In this MSc Thesis project Hyperion AC DC EOS06061AD C battery charger is used The Hyperion has charge discharge and storage modes Pb Mode is used to select lead acid batteries in Hyperion and charging current is chosen 300mA 6 series connected cells are charged at the same time due to the specifications Therefore total battery voltage is chosen 12V The most important specifications of Hyperion AC DC EOS0606iAD C battery charger is given in Table 1 Table 1 Specifications of Hyperion AC DC EOSO606iAD C Hyperion Input voltage range 11 15V DC Range of series connected lead acid battery 1 6 cells Charge current 100mA 6A max by 100mA steps for lead acid batteries Charge termination CV CC for le
22. data ir2117 pdf Kong Soon N Chin Sien M Yi Ping C Yao Ching H 2008 State of Charge Estimation for Lead Acid Batteries Based on Dynamic Open Circuit Voltage 2 IEEE International Conference on Power and Energy PECon 08 Johor Baharu Malaysia Krein P T Balog R 2002 Life Extension Through Charge Equalization of Lead Acid Batteries Accessed on 18 04 2013 Available at http windandsunpower com Download intelec02 pdf Linden D Reddy T B 2002 HANDBOOK OF BATTERIES Third Edition McGraw Hill New York Linear Technology 2008 LTC3862 Multi Phase Current Mode Step Up DC DC Controller Accessed on 20 04 2013 Available at http cds linear com docs en datasheet 3862fb pdf 54 Linear Technology 2010 LTC3890 60V Low Io Dual 2 Phase Synchronous Step Down DC DC Controller Accessed on 19 04 2013 Available at http cds linear com docs en datasheet 3890fc pdf Linear Technology 2013 LTC6804 1 LTC6804 2 Multicell Battery Monitors Mastech 2013 MS8221D DIGITAL MULTIMETER Accessed on 17 12 2013 Available at http www p mastech com images SPEC ms8221d 20ms8230b pdf Maxim Integrated 2008 Maxim MINIQUSB User Guide Accessed on 04 04 2013 Available at http datasheets maximintegrated com en ds MINIQUSB pdf Maxim Integrated 2010 MAX11068 12 Channel High Voltage Battery Sensor Smart Data Acquisition Interface Maxim Integ
23. sheet sss 45 Figure 32 Total lead acid battery voltage versus time seen 46 Figure 33 Load Discharging Curve of lead acid battery cell 19 s 46 Figure 34 Future BMS PMU Block Diagraf 2000002000 eerte teen tierce 50 vii LIST OF TABLES Table 1 Specifications of Hyperion AC DC EOS06061AD C Hyperion 8 Table 2 Characteristics of different rechargeable batteries Pistoia 2005 9 Table 3 Advantages and disadvantages of lead acid batteries compared to other rechargeable battery types Linden et al 2002 seen 10 Table 4 Characteristics of Lead Acid Batteries Broussely et al 2007 amp Pistoia 2009 10 Table 5 Open Circuit Voltage vs State of Charge of lead acid battery cell 13 Table 6 Definition of IC bus ianitor Pt p 16 Table 7 PC Command List Maxim Integrated 2010 aient 19 Table 8 C bus Address Bits Maxim Integrated 2010 steil n tata dd 20 Table 9 Jumper Configurations based on number of cells of MAX11068 EVALUATION KIDEBRACK NAE Bi goa odn b ebd a a teta atop a ceo tra ot a Co pedea dE 24 Table 10 Header P3 Cell Connections of MAX11068 EVALUATION KIT PACKA 25 Table 11 Jumper Configurations of MAX11068 EVALUATION KIT PACK A amp B 25 Table 12 Switch Configurations of MAX11068 EVALUATION KIT PACK A amp B
24. this data the command of address 0x01 register is sent The SETLASTADDRESS command is called after ROLLCALL command The write bit is added at the end of 7 bits broadcast address and it is sent on I2C bus Next to this data the command of address 0x01 register is sent After that two data bytes are 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 written to each device which is sent on PC bus The first data byte may be any value However the second data byte is written to address register of all devices Thereafter the PEC packet error checking byte is sent PEC byte is calculated from first four bytes The WRITEALL command is called after SETLASTADDRESS command The write bit is added at the end of 7 bits broadcast address and it is sent on IZC bus Next the command of address is sent with MSB first The lower and upper data bytes are added to the data respectively After the PEC byte is sent The PEC byte is calculated from first four bytes The WRITEDEVICE command is called after WRITEALL command The only difference of WRITEDEVICE and WRITEALL command is the address byte of l C bus of WRITEDEVICE command has fixed MSBs 0b10 in binary format pursued by the command of address is sent with LSB first in the place of broadcast address The READALL command is called after WRITEDEVICE command The write bit is added at the end of 7 bits broadcast address and it is sent on PC bus Next to this data the command byte is sent To change the dire
25. time 6 2 2 Excel Results The Excel sheet displays the measurement counter cell voltages cell SoCs date and time The measurement counter is updated every second 1 241 212 212 241 241 241 214 213 2 13 2 14 2 13 2 10 2 12 2 13 241 2 212 212 2 12 2 11 2 11 241 214 2 13 2 13 2 14 2 13 2 10 2 12 213 211 3 211 2 12 242 211 241 241 2 14 2 13 2 13 214 2 13 2 10 2 12 2 13 241 4 212 2 12 2 12 2 11 241 241 214 213 2 13 2 14 2 13 2 10 2 12 243 241 5 241 2 12 2 12 2 11 2 11 241 214 213 243 2 14 2 13 2 10 2 12 243 211 6 2412 242 2 12 241 241 241 2 14 2 13 2 13 2 14 2 13 2 10 2 12 2 13 241 7 241 212 212 241 241 241 214 213 2 13 2 14 2 13 2 10 2 12 2 13 211 8 241 212 212 241 21 21 214 213 2 13 2 14 2 13 2 10 2 12 213 241 9 2 12 242 242 241 241 241 2 14 2 13 2 13 214 2 13 2 10 2 12 2 13 211 10 211 212 212 241 241 2 11 2 14 2 13 2 13 2 14 2 13 2 10 2 12 2 13 241 11 2 12 2 12 2 12 241 241 241 214 213 213 214 2 13 2 10 2 12 2 13 241 12 2412 242 2 12 241 241 241 2 14 2 13 2 13 2 14 2 13 2 10 2 12 2 13 241 13 242 242 2 12 211 241 241 2 14 2 13 2 13 214 2 13 2 10 2 12 2 13 241 14 241 212 212 2 11 21 241 214 213 243 214 2413 2 10 2 12 213 211 Figure 30 Cell voltages and measurement counter displayed in Excel sheet From the Figure 30 the changes of each cell voltages with respect to the measurement counter can be obtained The first label is measurement counter After that the results of voltages of 24 cells are located in labels 6 RESULTS AND DISCUSSION
26. 0 min Cell Volt V 5 5 3 max Temperature Two auxiliary Two auxiliary Two auxiliary measurement inputs for 12 inputs for 12 inputs for every 12 cells cells cells Data rate 10 kHz to 200 N A Up to 1 MHz kHz Cost EVKit N A N A 150 IC only N A N A 15 25 First of all from the Table 17 we obtain that LTC6804 is the best choice if the designers have not had MAX11068 yet at the moment to design new Battery Management Systems because it is the only available EVKit or IC MAX17830 is Maxim Integrated s second generation next generation version of the MAX11068 high accuracy amp high voltage battery management solution Maxim Integrated MAX17830 12 Channel High Voltage Battery Sensor with Advanced SMBus Ladder and External Cell Balancing 2013 Since it is mentioned MAX11068 will be no longer produced Maxim Integrated Evaluation System for the MAX11068 2013 MAX17830 could be chosen instead of it for future designs In our MSc Thesis project MAX11068 was used as it was produced before and consequently available and MAX17830 is not available at the moment Furthermore MAX11068 has some advantages as well as some disadvantages over the LTC6804 The voltage range for whole pack without any external power of MAX11068 is greater than LTC6804 Moreover max series cells of MAX11068 are greater than LTC6804 On the other hand LTC6804 has more voltage measurement accuracy than MAX11068 and the data rate range of LTC6804 is gr
27. 1068 EVALUATION KIT PACK A amp B Jumper Position of Shunt JUO JU 100 On JUI JU 101 On JU12 JU112 Off JU13 JU113 1 2 JU14 JU114 2 3 JU15 JU115 2 3 JU16 JU116 1 2 JU17 JU117 2 3 JU18 JU118 1 2 JU19 JU119 1 2 JU20 JU 120 On JU21 JU 121 Off JU24 JU 124 On JU25 JU125 On JU26 JU 126 On JU28 2 3 JU128 1 2 JU31 JU131 JU32 JU132 On 25 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 Jumpers JUO JU1 JU100 and JU101 enable or disable the auxiliary inputs to measure external resistance temperature detector RTD components Maxim Integrated MAX11068 Evaluation System 2010 The negative temperature coefficient NTC RTD can be structured with auxiliary analog inputs to measure battery cell temperature Since the temperature measurement of battery cells is not a part of our PMU project the auxiliary inputs are not used via installing a shunt on jumpers JUO JU1 JU100 and JU101 The cell configuration switch SW101 is given in Appendix 1 and the cell connection switches are given in Appendix 2 Table 12 Switch Configurations of MAX11068 EVALUATION KIT PACK A amp B Switch Switch Position SWI1 SW101 Off SW21 SW22 SW121 SW122 On After the all configurations using a universal serial bus USB cable the MAX11068 Evaluation Kit Pack A is connected to personal computer PC via Arduino Due Arduino Due is connected to MAX11068 Ev
28. 12 2 13 90 2 11 2 12 85 2 1 2 11 80 2 09 2 1 75 2 08 2 09 70 2 07 2 08 65 2 05 2 07 60 2 04 2 05 55 2 03 2 04 50 2 02 2 03 45 2 01 2 02 40 2 2 01 35 1 99 2 30 1 98 1 99 25 1 97 1 98 20 1 96 1 97 15 1 95 1 96 10 1 94 1 95 5 1 94 0 According to the Table 5 the lead acid battery cell reaches 10096 SoC if the voltage level of that cell is greater than 2 14V 2 5 State of Health SoH Estimations Battery SoH is an important estimation to observe the battery performance According to Tanaami et al 2009 SoH estimations show how much the battery can supply its maximum capacity under usual charging or discharging conditions The battery aging comes up when the charge and discharge cycles of a rechargeable battery are increased In addition the battery aging can occur if the battery is used improperly during charging or discharging The battery aging is an important reason to affect battery life and capacity According to Huet 1998 the charging or discharging current magnitude DoD depth of discharge room temperature battery charge control method over charging or discharging storage type and duration are the factors that affect the battery SoH An early breakdown of the lead acid battery of the device can cause a problem since the electrical power consumption of that device is increasing by the time of progress Hence the battery SoH estimation is crucial and required for devices durin
29. D DISCUSSION 40 With this PMU GUI the users can be aware of what is going on the lead acid battery pack The plots make it easier to obtain the variations by the time of progress If the battery or cell status indicator is changed then the hardware should be fixed before any serious damage is caused This PMU GUI allows the lead acid battery for long life operation by monitoring the voltages and SoCs of 24 lead acid battery cells in a smart way Only monitoring the voltages and SoCs is not enough for long life operation However if the voltages and SoCs are not monitored then they could not be controlled The program immediately starts when it is run by the user The only user dependent function of program is Write to Excel function 6 2 Cell Measurement Results The Figure 24 shows the individual cell voltages and SoCs together with status indicator when the load is not connected at a given time Figure 24 Individual cell voltages and SoCs From the Figure 24 we can detect that Cell 19 s voltage status is less than other cells The status indicator shows OK However it is going to enter a critical level 1 9V in a time of period if it is not charged In addition Cell 12 and Cell 21 s SoC status are less than 40 and they should also be handled well According to the Figure 24 since not all cells are in a same voltage level the passive or active balancing might be applied to obtain the optimal performance of l
30. DERATIONS BASED ON MAX11068 17 3 1 1 Serial Data Line SDA and Serial Clock Line SCL According to the NXP Semiconductors 2012 the SDA and SCL are both bidirectional When the I C bus is not assigned any job the SDA and SCL levels are both HIGH 1 Since any device which may have metal oxide semiconductor MOS and bipolar technologies can be connected to I C bus the SDA and SCL levels are not defined as LOW 0 or HIGH 1 The levels depend on positive supply voltage of FET Vpp The low level input voltage Vi is set as 0 3Vpp and high level input voltage Vin is set as 0 7Vpp a xl a permitted Figure 8 PC bus bit transmission NXP Semiconductors 2012 From Figure 8 it is obtained that the data on SDA has to be stable when the clock signal is HIGH Moreover the LOW or HIGH level of SDA is changed when the SCL clock is LOW In addition for each transmitted data bit one clock pulse is produced Figure 9 START and STOP conditions NXP Semiconductors 2012 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 All transmissions that are generated by the master begin with START and end with STOP As observed from Figure 9 for SDA the START is acquired by a HIGH to LOW passing when SCL is HIGH On the other hand for SDA the STOP is acquired by a LOW to HIGH passing when SCL is HIGH Each byte is followed by an acknowledge ACK bit Data transfer is begun by most significant bit MSB first The ACK
31. IEW 11 It can be concluded from Table 4 that Cyclon D Cell Sealed lead acid batteries have different float voltage range than other types of lead acid batteries Furthermore the operating temperature range of Cyclon D Cell Sealed lead acid batteries is higher than other types of lead acid batteries Cyclon D Cell Sealed lead acid batteries can be used in telecommunications UPS energy storage electric vehicles solar power equipments aerospace etc Therefore from all reasons above the Cyclon D Cell Sealed lead acid batteries are used in our PMU project In addition the capacity of Cyclon D Cell Sealed Lead rechargeable 2V battery is equal to 2 5Ah 2 3 4 Future of Lead Acid Batteries According to Clarke 2011 cheap expansion manufacturing scale and 100 recycling of lead acid batteries have a key role in fast growing battery markets In addition lead acid batteries should satisfy the energy density requirement of Li ion batteries in future Moreover lead acid batteries may have less charging time higher life cycle and more direct current path to gain advantage over other batteries found in the industry Furthermore the manufacturing process steps and the materials or equipment that used in lead acid batteries can be reduced 2 4 State of Charge SoC Calculations SoC estimation is a crucial indicator for managing batteries and providing reliable operations for them It shows the amount of energy remained in th
32. List Maxim Integrated 2010 Name Function PEC Byte HELLOALL Setting the all device Not contain address via initializing the first device s address in the chain All other remaining devices are auto incremented ROLLCALL Determining of devices in Not contain the chain SETLASTADDRESS Determining which device Required from the host address is the last one WRITEALL Enabling a value to be Required from the host written to a register in all active devices at the same time WRITEDEVICE Writing the data to only a Required from the host certain device READALL Reading the data from a Send to the host certain device register for all devices in the chain According to Maxim Integrated 2010 the first two bits of HELLOALL have to be 1 Next 5 bits determine the address of first device in system management bus SMBus ladder The last bit is the R W bit and it must be 0 The 5 bits starting address is determined as the least significant bit LSB is the first bit The typical starting address is 0x01 Therefore the HELLOALL command becomes 11100000 in binary format It is equal to OxEO in hexadecimal format The ROLLCALL command should be called just after HELLOALL command When OxFF is returned it means that the host has addresses of all devices The ROLLCALL command is a read of address 0x01 The write bit is added at the end of 7 bits broadcast address and it is sent on PC bus Next to
33. N 1 100V i SDAU_B i lt GNDUB 02 5 duci e SDAU B U U i ALRMU_B L lt 02 8 102 7 ALRMU_B U i 1102 10 J102 3 c2 B U i i i 1 1102 12 J102 1 C12 8 C2 o VDDCPCB 1 i i R177 R192 0135 Koz 3102 19 i AAA CO ov i 1 20k 150 3 i U e k102 16 4102 155 N C C155 D134 I i O tuF OPEN f z 100V 1 i lt GNDUCB um JU132 C151 J102 18 1102 12 gt N C i 02 20 5 SHORT PC TRACE e A ALRMINC_B i ION NM Wis ALRMINC B 29 MAX11068 EVKit s cell configuration switch SW101 is given below Maxim Integrated 2013 cia B SW101 UE a SW101 A cit B DD e o 24 i i Jum o i i Sw101 8 i c10_B _ gt T 2 o 23 i i Juno 2 i i SW101 C i co B e 3 9 22 Ju109 2 i i swiot o c8_B gt eo o 2 i i wus i SW101 E i c7_B gt e o 29 i i JU107 o i SWIOI F ce 8 DD e o 19 i i JU106 o swore c5 B gt e o 8 i JU105 o swiot H C4 B aa i wos SW101 1 c3_B gt 9 18 1 i Juios i SWIO1 J c2 B e d 10 o 15 i i Ju102 9 SW101 K ci 8 DD oe o 4 i U 1 U 1 U SW 101 L co B 2 0 13 LU 60 APPENDIX 2 MAX11068 EVKIT CELL CONNECTION SWITCHES AND HEADERS MAX11068 EVKit s cell connection switches and headers are given below Maxim Integrated 2013 J8 SW21 P3 J108
34. SW121 P103 ym gem y _ 7777 i Fw R ee i if L U co A i SW21 A 1 cos DR i SWIZI A y i 1 i i U Jat o 1 1 K3 P3 2 4108 1 4 e u 4 o i lt P103 1 Pt03 2 1 1 U j I U caa D 1 Sw21 8 1 asl i Swi21 B i i U 1 L U 2 2 3 o 2 T ess es S sos 1 Zo m we P103 4 1 i I 1 1 i i c2 A 37 sw21 c i c23 54 1 swi2i c 1 i D i J08 eee a ee 5 F103 8 c 5 4 la D 4 T u M mh m e OD 1 1 i D L U c3 A O 4 i Sw21 0 i ex B 5 4 i swi21 D i U j U U J A e 4 T 3 7 P3 8 gt si08 4 gt 4 o i 603 7 P103 1 i 1 i i i eal SW21 E 1 oslo Swi2TE i I i ly 5 5 i 48 8 3 o 2 T 3 9 P3 10 gt Jt08 85 1 3 o oa 103 9 P103 10 i 1 i U L U c5_A gt i Sw21 i c5 8 5 4 SWWN F 1 i 1 U Ja 8 93 93 12 Joa Di a HE P103 12 1 1 1 1 1 i i c amp A 4 Sw21 G 1 ceB 5 4 swizTG U i i i U U U e PN LA T 4 o 103 13 P103 13 gt J U 1 C7ALD SW22 A i c 8 D4 i Swiz2 a i U U Ig i 48 8 24 o 1 T ess P3 iy sos 8 i o im oss Pos 1 1 1 U U I U ca A 5 i 5w22 8 1 ce B 54 sw122 8 I 1 i Uu 18 9 gt 3 c 2 T 3 7 P3 18 gt so8 3 4 gt o 2 i ew Pi03 18 gt 1 1 1 1 i D I U coal 5w22 C 1 I css OD w122 C i i i i 1 t U U U v8 gt oe
35. TAMPEREEN TEKNILLINEN YLIOPISTO TAMPERE UNIVERSITY OF TECHNOLOGY SELIMCAN DEDA SMART BATTERY POWER MANAGEMENT UNIT Master of Science Thesis Examiners Prof Nikolay T Tchamov MSc Jani Jarvenhaara Examiners and topic approved by the Faculty Council of the Faculty of Electrical Engineering on 3 April 2013 ABSTRACT TAMPERE UNIVERSITY OF TECHNOLOGY Master s Degree Programme in Electrical Engineering DEDA SELIMCAN Smart Battery Power Management Unit Master of Science Thesis 73 pages 6 Appendix pages February 2014 Major Radio Frequency Electronics Examiners Professor Nikolay T Tchamov and MSc Jani Jarvenhaara In this project the ways how a Smart 48V Battery Power Management Unit PMU which uses lead acid batteries can be designed for wide range of industry usage are researched PMU is a modified version of Battery Management System BMS Since the batteries are designed for charging and discharging for their life they need an optimum way to be monitored and or balanced to increase their efficiency The PMU system monitors the voltages and State of Charges SoCs of whole battery module amp individual cells PMU ensures reliable and safe battery operations MAX11068 is used in the project to meet the monitoring and or balancing requirements of the BMS and thus PMU However only using the MAX11068 is not enough for designing a PMU In addition to the MAX11068 a microcontroller Arduino Due and a comprehensive Java
36. X11068 EVKits From the Figure 19 the connection of J3 Header of MAX11068 Evaluation Kit PACK A and Arduino Due can be seen The serial clock line SCL serial data line SDA faster wakeup FWUP backup voltage VDDBU and ground GND pins of Arduino Due is connected to J3 Header of MAX11068 Evaluation Kit PACK A which provides the PC communication Since the SHDNINA net should be pulled up to 3 3V Maxim Integrated MAX11068 Evaluation System 2010 digital pins 52 amp 53 of Arduino Due are connected to J3 Header of MAX11068 Evaluation Kitt PACK A because the input output I O pins run at 3 3V Figure 19 Arduino Due amp J3 Header of MAX11068 Evaluation Kit PACK A Connection 33 4 POWER MANAGEMENT SYSTEM DESIGN Furthermore the constant current load is illustrated in Figure 20 When the voltage is applied on the battery voltage Vbat the gate resistor Rg turns the metal oxide semiconductor field effect transistor MOSFET IRL2910 ON In addition the base emitter voltage VBE on of NPN transistor BC549 is equal to 0 7V The relationship between the sensing resistor Rs and drain current Ip is given in the equation 12 VsE om _ 0 7V b bb Hence Ip is controlled by the Rs value In the load Rs is chosen as 0 750 Hence the constant current through the load is set as approximately 0 9A When the potential difference between Rs reaches Vpg on the transistor is turned ON The equation for power dissipa
37. ad acid batteries 2 LITERATURE REVIEW The Hyperion AC DC EOS06061AD C battery charger is shown in Figure 6 Figure 6 Hyperion AC DC EOS0606iAD C battery charger Hyperion 2013 2 3 3 Comparison of Rechargeable Batteries In this part the characteristics and advantages disadvantages of lead acid batteries compared to other rechargeable battery types are explained Table 2 Characteristics of different rechargeable batteries Pistoia 2005 Characteristics Cell Lead Acid Li ion Ni MH Ni Cd Alkaline Specific Energy 30 to50 150to 190 60 to 90 40 to 60 80 Wh kg Fast Charge Time 8 to 16 2to3 1 1 2 to 3 h Overcharge high very low low moderate moderate Tolerance Self Discharge 3 5 30 20 0 3 month Nominal Cell 2 21 1 25 1 25 1 5 Voltage V Operating 20 to 60 20 to 60 20 to 60 40 to 60 0 to 65 Temperature C only discharge 2 LITERATURE REVIEW 10 Hence it can be observed from the Table 2 that lead acid batteries have different characteristics over other rechargeable batteries According to Linden et al 2002 the advantages and disadvantages of lead acid batteries are given in the Table 3 Table 3 Advantages and disadvantages of lead acid batteries compared to other rechargeable battery types Linden et al 2002 Advantages Disadvantages Widely used and manufactured globally The energy density Wh kg is low Good perfor
38. aluation Kit Pack A s J3 header Table 13 J3 Header Pinout of MAX11068 EVALUATION KIT PACK A Pin Number Net Association 1 SHDNINA 3 SDALA 5 GNDLA 7 SCLLA 9 Not Configured i SHDNA 13 Not Configured 15 Not Configured 17 Not Configured 2 4 6 8 10 12 14 16 18 19 GNDLA 26 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 27 3 4 1 MAX11068 EVKit SMBus Ladder MAX11068 Evaluation Kit utilizes PC communication to cascade up to 31 MAX11068 devices via routing PC communication to headers J1 amp J2 for Board A and J101 amp J102 for Board B Since one shipped MAX11068 Evaluation Kit involves two boards boards A amp B 16 MAX11068 Evaluation Kits are required to acquire 31 device SMBus ladder Maxim Integrated MAX11068 Evaluation System 2010 In Figure 14 the MAX11068 EVKit SMBus Ladder can be found when Board A is the first board Maxim Integrated MAX11068 Evaluation System 2010 i01 ste iti J101 J102 A B A B Ji 109 Ji J103 Figure 14 MAX11068 EVKit SMBus Ladder when Board A is first board Maxim Integrated MAX11068 Evaluation System
39. at http www atmel com Images doc11057 pdf Begovic M 2012 Electrical Transmission Systems and Smart Grids Springer Bergveld H J Kruijt W S Notten P H L 2002 Battery Management Systems Design by Modelling Kluwer Academic Publishers Boston Broussely M Pistoia G 2007 Industrial Applications of Batteries First Edition Elsevier B V Amsterdam The Netherlands a3 Clarke R S 2011 B LAB CHANGING THE GAME FOR LEAD ACID Applied Intellectual Capital Alameda Accessed on 24 09 2013 Available at http www battcon com PapersFinal201 1 ClarkeStephenPaperDONE2011_13 pdf Claus D 2008 Materials and processing for lithium ion batteries Volume 60 Issue 9 pp 43 48 Enersys Cyclon 2008 US CYC ApplicationManual 007 04081 Fairchild Semiconductor 2013 LM78XX LM78XXA 3 Terminal 1 A Positive Voltage Regulator Accessed on 19 04 2013 Available at http www fairchildsemi com ds LM LM7805 pdf Huet F 1998 A review of impedance measurements for determination of the state of charge or state of health of secondary batteries Elsevier Science S A Hyperion HYPERION AC DC EOS0606iAD C USER S MANUAL Accessed on 23 04 2013 Available at http media hyperion hk dn EOS EOS0606iAD acdc A MAN EN pdf International Rectifier 2007 IR2117 S IR2118 S amp PbF Accessed on 20 04 2013 Available at http www irf com product info datasheets
40. attery Open Circuit Voltage vs State of Charge Enersys Cyclon 2008 The Figure 7 is valid to within 2096 of correct SoC of battery cell if the cell has not been applied any charge discharge operations within the last 24 hours In addition the Figure 7 is valid to within 596 of correct SoC of battery cell if the cell has not been applied any charge discharge operations within the last 5 days Therefore the open circuit voltage OCV of lead acid batteries is dependent of charging discharging rates and the amount of time they have been disconnected from charger The Cyclon battery should have the required overcharge to reach long battery life Under proper charging conditions the Figure 7 is valid for ten years Enersys Cyclon 2008 The proper charging method for Cyclon batteries is Constant Current Constant Voltage CC CV method which is explained in section 2 3 2 1 Furthermore it is observed from the Figure 7 that the SoC of lead acid battery is a linear function of open circuit voltage The battery cell is considered as fully charged when the OCV is greater than 2 14 V cell and fully discharged when the OCV is less than 1 94 V cell The relationship between OCV and SoC of a lead acid battery cell is given in the Table 5 2 LITERATURE REVIEW 13 Table 5 Open Circuit Voltage vs State of Charge of lead acid battery cell OCV V SoC gt 2 14 100 2 13 2 14 95 2
41. bit demonstrates that the data byte transmission is done successfully When ACK is sent the receiver sets the SDA as LOW However the ACK bit does not ensure the data integrity The negative acknowledge NACK bit is generated 1f there is no receiver on I C bus or the receiver is not able to receive any data byte When NACK is sent the receiver sets the SDA as HIGH m ATA INO I lt Hl Hl LOI NES START ADDRESS RW ACK DATA ACK STOP Figure 10 Complete Data Transfer NXP Semiconductors 2012 In Figure 10 the slave address is sent after START The slave address is seven bits long It is followed by the read write R W R W is a data direction bit If R W is zero then the master writes to slave On the other hand if R W is one then the master reads from slave The data byte transmission is ended by STOP which is generated by the master For example when the master generates a Write it sends data bits and receives an ACK bit If the slaves are slower than masters then the slaves can spread the clock pulse via setting SCL low in a short span of time until it is able to make a new data transmission 18 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 3 1 2 lC Command List In the Table 7 the commands together with their functions are given If the device configuration is addressable then the initializations given in Table 7 is not used In addition Table 7 is specific for the MAX11068 Table 7 PC Command
42. c Thesis project It is due them that I have enjoyed my working time in RF Integrated Circuits Laboratory Next I would like to address my friends from Finland I have met so many nice people from different cultures during my stay in Finland You made my time so special and memorable in Finland Additional thanks go to my special friends from Turkey and all around world for providing support and valuable friendship that I need throughout my life To Meri a lar my oldest friend you are truly more than a special friend a brother I call you Thank you for always giving me motivation to work harder I am indebted to my mother for teaching me to hold my head high in life my father for giving me advices when I am undecided about anything in life and my family for their priceless help and support I am truly gifted to have you as part of my life Lastly I want to dedicate my MSc Thesis to soul of my dear grandmother who untimely passed away during the last stage of my MSc Thesis work and my dear uncle who passed away long time ago I believe if they were still alive they would be proud of me Selimcan Deda Tampere February 2014 ill CONTENTS EISUOL Fioures pe osa es id Sata nk ja a SSO e aj Here i ni dd V Eist f Lablgs nost soto Ares ie at setius d ek opto m ht vii Iastot AA DIME VIATIONS Sc seio teo E o etam pd lean eid fate apu viii List of iub Me H X ls Imrodu lon se eo miee no A
43. ceed their operating levels Also if the number of series connected battery cells create a high voltage level for applications then the cell balancing should be implemented in future design to prevent the potential damage The active balancing method can be applied for this purpose because the active balancing method is faster and the power efficiency of it is higher than the passive balancing method Consequently the control of the PMU can be mainly divided into four parts Avoidance of over undercharging of battery cells monitoring battery temperature monitoring battery output current and controlling the switching process 52 REFERENCES Andrea D 2010 Battery Management Systems for Large Lithium Ion Battery Packs Artech House Arduino Arduino Due Accessed on 18 04 2013 Available at http arduino cc en Main arduinoBoardDue Arduino SAM3X Arduino Pin Mapping Accessed on 18 04 2013 Available at http arduino cc en Hacking PinMappingSAM3X Arduino Arduino Uno Accessed on 18 04 2013 Available at http arduino cc en Main arduinoBoardUno Arduino Wire Library Accessed on 18 04 2013 Available at http arduino cc en reference wire Arendarik S 2012 Active Cell Balancing in Battery Packs Freescale Semiconductor Inc Accessed on 18 04 2013 Available at http www freescale com files 32bit doc app_note AN4428 pdf Atmel SAM3X A Accessed on 18 04 2013 Available
44. ction of bit stream the repeated start SR is sent On the contrary this time the read bit is added at the end of 7 bits broadcast address instead of the read bit and it is sent on I C bus In Table 8 the address bits of commands are shown The Broadcast Address is used for ROLLCALL WRITEALL and READALL commands Table 8 I C bus Address Bits Maxim Integrated 2010 Command 7 6 5 4 3 2 1 R W Broadcast Address B7 B6 B5 B4 B3 B2 B 1 0 Default 0 1 0 0 0 0 0 1 0 HELLOALL 1 1 AO Al A2 A3 A4 0 WRITEDEVICE 1 0 AO Al A2 A3 A4 0 In the Smart Battery PMU project the PEC bytes are calculated via Pseudo Code Algorithm for a CRC 8 PEC Calculation Maxim Integrated 2010 MAX11068 utilizes SMBus PEC algorithm to sustain the completeness of data The CRC 8 algorithm supports SMBus PEC mechanism to carry out calculations The CRC 8 polynomial C x is shown below C x x8 ex 4 x41 At first C x is initialized to zero The byte is XORed exclusive ORed with C x for each input byte and called as Remainder When MSB is equal to one then the remainder is left shifted and XORed with eight LSBs of the C x When MSB is equal to zero then the remainder is left shifted by one bit This is applied until eight left shifts are acquired Next the transaction is repeated on the next input byte using current C x When the process of all input bytes is completed the last result is the output byte of C x
45. ctor field effect transistor most significant bit negative acknowledge NTC N A OCV OV PC PEC PMU PWM RF RTD SCL SDA SMBus SoC SoH SLI SR SW TV TX UPS USB UV Vpp VDDBU Vin Vit XOR ix negative temperature coefficient not available open circuit voltage overcharge personal computer packet error checking power management unit pulse width modulation radio frequency resistance temperature detector receiver read write serial clock line serial data line system management bus state of charge state of health starting lighting ignition repeated start switch television transmitter uninterruptible power system universal serial bus undercharge positive supply voltage of FET backup voltage high level input voltage low level input voltage exclusive OR LIST OF SYMBOLS ADC out C x DoD FCC Ip Pp O max Opassed Ostart Rg RM Rs SoC SoH Vbat VBE output of analog to digital conversion CRC 8 polynomial depth of discharge full charge capacity drain current power dissipation maximum battery capacity passed charge charge at the beginning gate resistor remained capacity sensing resistor state of charge state of health battery voltage base emitter voltage 1 INTRODUCTION The devices that obtain some or all of their running power from a battery have become widespread in various industries The fast enlargement of the use of EVs portable electronic devices
46. d Power Management Unit PMU for Rechargeable Battery Operated Implantable Biomedical Telemetry Systems Bioinformatics and Biomedical Engineering iCBBE 4 International Conference Chengdu Wikipedia 2009 Grid storage energy flow Accessed on 12 04 2013 Available at http en wikipedia org wiki File Grid storage energy flow png Williams D 2012 Configuring the bg34100 Data Flash Texas Instruments 57 APPENDIX 1 MAX11068 EVKIT CELL CONFIGURATION HEADERS AND SWITCH MAX11068 EVKit s cell configuration header J101 is given below Maxim Integrated 2013 JU125 R140 SHONE C 9 o o V WNw lt ll SHONINCB 20k GNDLB J101 SHDNINB1 Hoda a NN JU126 l R186 _ lt 01 2 J0 gt oo NANN lt SHDNINB U ik eun R183 NA N setts 0 ae R184 AVN SDALB 0 I 1 T T i Js RMLB1 R185 1 T l AAN lt ALRMLB 0 R139 A VVV lt __ SHDNINCB 7 1k I I 101 14 s101 13 gt aourai R154 NIN N ALRMOUTCB O 58 MAX11068 EVKit s cell configuration header J102 is given below Maxim Integrated 2013 C12_B GNOUS C12_8 GNDU4 JU131 GNDU3 J102 VDDCPB l C150 fo 4 CR R101 l R191 DIE gt e 4d2 2 no2 5 AA WN dO crre SHORT 20k 150 3 U PC TRACE L ro2 4 0102 s cnc a SCLU_B C154 dese I i ce 0 1uF OPE
47. d divided to 24 to find total battery SoC 39 6 RESULTS AND DISCUSSION For testing the Power Management Unit PMU the software titled RFIC PMU GUI is used A new graphical user interface GUI is designed for because it allows to record to excel displays State of Charges SoCs and it is easy to use 6 1 Graphical User Interface The main GUI window given in Figure 23 displays the voltage and SoC status of 24 cells of the lead acid battery pack The total battery voltage is calculated by adding all series individual cell voltages Write to Excel button is included to write measurement data to excel sheet The PMU GUI is updated instantaneously The data update rate including the delay is set by microcontroller For each cell there is a status indicator If that status indicator shows OK it means the cell is in a safe condition If that status indicator shows OV then the cell is overcharged the cell voltage is higher than 2 15V On the other hand if that status indicator shows UV then the cell is undercharged the cell voltage is less than 1 7V Both the over amp under voltage values are set in Java code and cannot be changed in GUI Differently from displaying each cell the GUI also shows the total lead acid battery pack voltage and SoC It also plots total lead acid battery SoC and voltage versus time Rev 1 0 2V 2500 mAh Rechargeable Lead Acid Cells Figure 23 PMU GUI without charts 6 RESULTS AN
48. e balancing method is higher than the passive balancing method but the active balancing method is more complex and expensive than the passive balancing method Krein et al 2002 The cell balancing is optional for series connected 24 battery cells in this smart battery PMU project However hundreds of battery cells totaling hundreds of volts are required to power electric motors Miller 2012 If hundreds of series connected battery cells are used for applications then the cell balancing should be implemented to increase the efficiency of battery powered devices and systems 2 3 Lead Acid Batteries 2 3 1 The History and Present of Lead Acid Batteries The first practical lead acid battery was invented by Gaston Plant in 1860 Linden et al 2002 and it was the first rechargeable battery for industrial and commercial use Plant s lead acid battery cells had a low charging capacity Following Plant s inventions lead acid batteries were developed further and they are being developed now The lead acid batteries are still popular and manufactured globally although they are older than other rechargeable batteries Typically lead acid batteries are nowadays used in automotive electric vehicle submarine uninterruptible power system UPS television TV radio and alarm systems industries 2 LITERATURE REVIEW 7 2 3 2 Charging Lead Acid Batteries The recharging process is crucial for batteries to secure the optimum life for them
49. e battery It prevents unpredictable and unwanted energy loss of the battery system It also demonstrates if the battery cell is overcharged or not Hence it provides a longer life for batteries Kong Soon et al 2008 2 4 1 The SoC Calculation Methods There are different ways to calculate SoC of lead acid batteries One solution method for lead acid battery SoC estimation is presented by Pang et al 2001 The approach of Pang et al 2001 to calculate SoC of lead acid batteries is based on estimating the open circuit voltage OCV of the lead acid battery and then providing a linear relationship between OCV and SoC According to Pang et al 2001 OCV p a SoC 1 where p is the lead acid battery terminal voltage when SoC is equal to 0 when lead acid battery charge is drained and a is obtained via putting the OCV and p values in equation 1 when SoC is equal to 100 when lead acid battery is fully charged 2 LITERATURE REVIEW 12 Additionally the relation between Cyclon cell voltages and SoC is based on the Figure 7 According to Enersys Cyclon 2008 SoC of Enersys Cyclon battery can be calculated using the curve given in the Figure 7 Cyclon Battery Open Circuit Voltage vs State of Charge 2 15r r r r r T 2 1 o S 2 05 gt z 9g o 2 c o o O 1 95 1 9 gt r r T L 10 20 30 40 50 60 70 80 90 100 State of Charge 96 Figure 7 Enersys Cyclon B
50. ead acid battery pack Furthermore all lead acid cells are in a safe voltage range because none of them is overcharged or undercharged 6 RESULTS AND DISCUSSION 41 The SoC icons are defined in GUI as given in Table 19 The intervals are defined based on Table 5 Table 19 SoC and SoC Icon with respect to it SoC SoC Icon 90 100 80 90 70 80 60 70 50 60 40 50 30 40 20 30 10 20 0 10 6 RESULTS AND DISCUSSION 42 6 2 1 GUI Chart Results The measurement result at a certain time is removed from the charts after one hour In other words measurement results last for one hour in GUI charts and new measurement results are shown The measurement results shown in Chapter 6 2 1 are taken without using load In Figure 25 variation of total 24 cells battery SoC in 15 seconds is given O Battery Soc Figure 25 Total Battery SoC vs Time The small fluctuations can be seen in 15 seconds from Figure 25 O Battery SoC Figure 26 Total Battery SoC vs Time in a different period of time The whole 24 cells battery SoC remains almost in a same level 48 in one hour However in some periods the variations can be observed from Figure 26 6 RESULTS AND DISCUSSION 43 In the Figure 27 the variation of total 24 cells battery voltage in 15 seconds is given Battery Voltage vs Time ET O 3 o gt LTT 9T 8T T 9T 6T T 9T
51. eater than MAX11068 Therefore the designers should select the right BMS EVKit based on their requirements Apart from these Texas Instrument s bq34z110 which is a lead acid fuel gauge can be the other option to monitor and state the SoC and SoH of a battery Texas Instruments 2012 However it does not have any balancing and protection solution Therefore an additional balancing and protection board is needed Thus the functionality of bg34z110 is less than MAX11068 3l 32 4 POWER MANAGEMENT SYSTEM DESIGN The complete measurement system which is illustrated in Figure 16 is consisted of four major parts e One 48V battery pack of series connected 24 lead acid cells e Two MAX11068 evaluation kits EVKits e Arduino Due e Constant Current Load Arduino Due p4eog DAA g 890TTXVIAI Lead Acid Battery Setup peo 3ueuun3 JUEJSUOJ paeog JAJ 890TTXVIAI Figure 16 The complete measurement system The connections of lead acid battery and Arduino Due to the MAX11068 EVKit are given in Figure 17 MAX11068 EVKit Board B MAX11068 EVKit Board A Figure 17 Connection Setup of MAX11068 4 POWER MANAGEMENT SYSTEM DESIGN The series connected 24 cells lead acid battery design is given in Figure 18 Figure 18 Series connected Lead Acid battery design In addition to the wires given in Figure 18 there are also wires which used to connect the battery cells to MA
52. en in Figure 3 Road consumed load power Fjen generated power with no energy storage Fjen generated power with energy storage Ftore energy flow to storage with energy storage release of stored energy to grid Power MW End storage of generated energy 0 00 6 00 12 00 18 00 0 00 1d Time Figure 3 Power in MW vs time Wikipedia 2009 It is obtained from the Figure 3 that the electrical energy which is produced by natural resources is varied during the day according to different conditions It directly affects the energy storage However the energy resources should be adjusted well if there is no energy storage For this purpose PMU can be used for distributed energy storage The main challenges of battery energy storage are controlling battery lifetime power delivery providing safety and handling costs Rahimi Eichi et al 2013 Those challenges can be completed via PMU According to National Geographic 2004 the oil supplies of world are going to be depleted in 2057 Therefore battery powered EVs are going to be needed in future for 2 LITERATURE REVIEW 5 providing required energy The PMU is going to play a crucial role in controlling and optimizing energy storage devices and systems in EVs accurately Figure 4 shows the flexibility supply curve Supply Side High Concentrating Electricity Flexibility Cost Storage The relative order of these is Low conceptual only Cost Increasi
53. erial data line SDA and serial clock line SCL are required and it is exactly software defined e All PC bus compatible devices communicate directly with each other via C bus e Masters can run as master transmitters or as master receivers They control the P C bus by sending data and addresses e It has collision detection clock synchronization and arbitration properties to block data overlap if two or more masters simultaneously begin data transfer e Permits a system to be changed easily by clipping or unclipping ICs integrated circuits to or from the bus without affecting any other functions of I C bus The I C bus interfaces are not required to be changed SDA and SCL convey the information between devices that connected to C bus The devices that connected to C bus have their unique addresses More importantly for the PMU projects PC communication provides very low current consumption high noise independence and broad range of the supply voltage and temperature Table 6 Definition of P C bus terminology Term Task Transmitter Sends data to C bus Master Begins a transfer creates clock signals and ends a transfer Synchronization Synchronizes clock signals of more than one device Arbitration If more than one master simultaneously attempts to control IZC bus only one is supposed to do so the other master loses the arbitration and waits until it is allowed to begin transmission 3 SYSTEM CONSI
54. function called cell balancing Cell balancing can be either active or passive Andrea 2010 2 LITERATURE REVIEW 6 When the lead acid battery cells are connected in series the current has a direct effect on all of the cells If the cell voltages start to differentiate the charges become unbalanced which may cause a battery malfunctioning for very long cell series strings at the end Hence a battery balancing mechanism can be used to prevent this potential failure Krein et al 2002 The capacity of a lead acid battery can be maximized with cell balancing by extending two limiting lowest amp highest points Arendarik 2012 Those two limits are defined by one cell in a balanced battery The charge is removed via preventing the charging current from the most charged cell and an extra charging current is provided to weakest charged cell In passive balancing the energy is squandered as heat and in active balancing the energy is transmitted between cells The passive balancing method of array of cells in series can be used for lead acid batteries Krein et al 2002 On the contrary the active balancing method is not depending on chemical properties of the battery cells There are both advantages and disadvantages of passive and active balancing The passive balancing method wastes power but its implementation is easier than the active balancing method On the other hand the active balancing method is faster and the power efficiency of activ
55. g the 2 LITERATURE REVIEW 14 process The Gas Gauge Algorithm can be used to estimate SoH The equations of Gas Gauge Algorithm to estimate SoH are given in following equations step by step Texas Instruments 2006 DoD 1 SoC 2 Simply the depth of discharge given in the eguation 2 is the complement of state of charge The gas gauge updates data on DoD based upon OCV open circuit voltage readings during a relaxed mode for each cell individually Texas Instruments 2006 As it is illustrated in figure given in Appendix 4 the subseguent DoD measurements are taken when 30 minutes elapsed in the relaxation mode After that DoD measurements are taken every 100 seconds Opassed lQ Q 3 where O is the first passed charge from the fully charged state and similarly O is the second passed charge from the fully charged state Qpassea is set to zero for every DoDo update passed Q max oe 4 where SoCi Q 5 and similarly SoC2 Q gt 6 In the equation 4 Qmax denotes the maximum capacity of the battery has Qmax is updated when AP A4uV ls 7 dt The equation 7 denotes the rate of instantaneous voltage change over time volts per second As it is obtained from the figure given in Appendix 4 Qmax is also updated when the maximal time is exceeded RM DoDyinai DoDstart x O max 8 Thus the Gas Gauge Algorithm utilizes DoD and Qmax total chemical capacity informations to estimate the RM remaini
56. ical Y Automotive Industry i e Electric and Hybrid Vehicles Y Renewable Energy Systems i e Solar Wind Green and Smart Sustainable Grid Renewable Energy Systems v Military i e Military Radios Navigators i e global positioning system GPS and Y Portable Medical Systems i e Heart Monitors and Defibrillators S In Figure 2 four application areas of PMU are shown forklifts golf carts shavers and electric vehicles respectively J Figure 2 Some examples of application areas of PMU 2 LITERATURE REVIEW 4 Nonetheless since a smart battery PMU prolongs the battery life it can be used to reduce the cost of vehicle during its entire lifetime Therefore electric vehicle EV batteries get vehicle manufacturer s attention According to Claus EVs can decrease the gasoline consumption up to 75 2008 Moreover according to the Boston Consulting Group Inc 2010 in 2020 the Electric Vehicle batteries market is expected to reach US 25 billion in Western Europe Japan United States and China High quality reliable safe monitorable and controllable batteries are needed to meet those expectations and to optimize life of the EVs Hence EV manufacturers should consider not only batteries but also PMUs in rapidly growing EV markets Furthermore the energy storage curves of load power generated power with and without energy storage and energy flow to storage for the experiment of one day are giv
57. ing to be discussed further The importance of SoC and SoH estimations are going to be explained Thereafter the setup process of PMU is going to be stated The flowchart of smart battery PMU programming is going to be illustrated Next the results of PMU are going to be given and discussed After that the conclusion of PMU project is going to be drawn Lastly the continuation design of work is going to be stated 2 LITERATURE REVIEW 2 1 What does Battery Management System BMS mean According to Andrea 2010 BMS means that to monitor all cell voltages protect the battery cells estimate the battery s state of charge extend battery life maximize the battery s performance and control the load 2 1 1 The Functions of Power Management Unit PMU The PMU a modified version of a BMS has crucial power functions in addition to its battery management functions Andrea 2010 This is the main difference of BMS and PMU The main function of BMS is to protect all battery cells via keeping them within a safe operating range Furthermore the top balancing approximately 100 State of Charge SoC is preferred In brief the BMS is an intelligent charging discharging system Additionally the battery operated devices and systems have to be managed to work in their optimum levels The battery operated devices can be consisted of a large number of battery cells and so high voltage levels For this purpose the PMU can be designed to pro
58. ition Interface 2010 Maxim Integrated Automotive Product Guide 2012 and Comparison of Selected BMS Boards High Voltage Battery Sensor Linear Technology LTC6804 1 LTC6804 2 Multicell Battery Monitors 2013 Table 17 Comparison of Different BMS Evaluation Kits Smart Data Properties MAXIM INTEGRATED LINEAR TECHNOLOGY General Part No MAX11068 MAX17830 LTC6804 EVKit EVKit Demo Board Availability Allversions Future Product Available are not recommended for new designs Voltage Range 6V to 1 4kV OV to 2 48kV 11V to 750V for whole pack approximately approximately approximately without nominal nominal nominal external power Cells Topology Modular Modular Modular Design 12 Design 12 Design 12 cells board cells board cells board Series cells 4 4 4 min Series cells 372 372 192 max no isolators Balancing On chip External External External resistors passive resistors are resistors are are needed needed needed External External External External resistors passive resistors and resistors and and MOSFETs are MOSFETs are MOSFETs are needed needed needed IC Typical 13 N A 35 Current Standby uA Drain Typical 2 N A 0 45 Operating mA 30 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 Typical Balance 250 N A N A mA Readings Voltage 0 25 lt 5 0 1 0 03 measurement mV Offset accuracy Voltage Cell Volt V 0 0
59. mance in at low and high temperatures Hard to be produced in small sizes High electrical turnaround charge efficiency 70 80 which compares outward discharge energy with inward charge energy Not possible to store in discharged condition High nominal cell voltage but less than Li lon Wheeled and stationary usage is limited High overcharge tolerance Thermal runaway can occur if the charging is not proper Explicit SoC demonstration Transportation limitations Less maintenance need Depending on number of cells the battery pack might be heavy According to Broussely et al 2007 and Pistoia 2009 the characteristics of lead acid batteries are given in the Table 4 Note that the Enersys Cyclon D Cell Sealed lead acid batteries are used in our PMU project The recommended EODV end of discharge voltage with respect to the discharge rate is given in table in Appendix 3 Table 4 Characteristics of Lead Acid Batteries Broussely et al 2007 amp Pistoia 2009 Lead Acid System Voltage Range Operating Application Areas Float Temperature C V Sealed 1 8 to 2 40 to 60 SLI starting lighting 1 8 to 2 40 to 55 ignition cars aircrafts ships Traction electric 1 8 to 2 20 to 40 trucks road vehicles Stationary 1 8 to 2 10 to 40 telecommunications UPS energy storage Cyclon D Cell 1 93 to 2 14 65 to 80 Sealed 2 LITERATURE REV
60. ng Renewable Energy RE Penetration Figure 4 Cost vs Increasing Renewable Energy Penetration Begovic 2012 Figure 4 describes the various approaches of ensuring system flexibility which is reguired for defragmenting renewable energy sources It also shows the variation in conceptual cost demand of several systems which ensure the integration in electrical system including supplemental flexibility The PMU technology may help to manage the system and decrease risks within this chain The improvement of 48V EV motors via PMU with battery fuel gauges provides some opportunities in electric vehicles industry The PMU is able to monitor the battery status and it may control the battery recharging via energy recovery Pistoia 2005 In 2011 some German automobile manufacturing companies proposed using 48V electrical system standard to acguire more power than the systems using 12V electrical system standard while considering 60V electric shock limit of EVs for safety issues Miller 2012 Therefore EVs need a leading edge technology such as PMU 2 2 Cell Balancing Methods for PMU The PMU may protect the battery by stopping the charging current if any cell voltage exceeds the limit Moreover if the temperature also exceeds the limit then the PMU can stop the charging current to protect the battery Similarly if any cell voltage drops below the limit then the PMU may stop the discharging current For those operations the PMU uses a well known
61. ng capacity FCC Qstart Qpassea RM 9 where Qstat denotes the passed charge which makes DoD equal to DoDo Qstart is equal to zero for a fully charged battery DoDo stands for the last DoD reading before charging or discharging FCC full charge capacity is the passed charge quantity from fully charged condition to the system termination voltage The passed charge must be higher than 37 of design capacity to allow the occurrence of an update In other words 2 LITERATURE REVIEW 15 FCC is the available capacity at the present charging or discharging rate FCC depends on the temperature at a time of measurement and load Consequently the formula to calculate SoH is given in the equation 10 Williams 2012 e FCC 11 Design Capacity In brief the SoH monitors the chemical degradation and shows when the battery SoH should be replaced 15 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 The system considerations given in this chapter describe MAX11068 which is used in this Smart Battery Power Management Unit PMU project 3 4 Inter Integrated Circuit IC Communication PC is a multi master bi directional 2 wire bus for efficient inter IC control Multi master means more than one device capable of controlling bus can be connected to it However only one master is active at any time It maximizes hardware efficiency and circuit simplicity Some of crucial features of EC are listed below NXP Semiconductors 2012 e Only s
62. oad sides Otherwise the Arduino Uno cannot control the switches as its operating voltage is 5V Furthermore the Arduino Uno requires input voltage between 7V to 12V to operate This operating voltage is gained through a DC DC step down process For this purpose LTC3890 DC DC step down converter is added to design LTC3890 takes the 48V input voltage and gives 12V output voltage Linear Technology 2010 Additionally the MAX11068 EVKit is used as BMS The inter integrated circuit PC communication and control of MAX11068 is provided by the microcontroller The LDO is optional but it provides filtering and drops out the output voltage of LTC3890 LM7810 can be used as a LDO in this design to drop 12V out to 10V Fairchild Semiconductor 2013 The load part is consisted of MOS switch and the light emitting diodes LEDs which are used as a load The load is connected to MOS switch and the output of 24 cell lead acid battery Nevertheless the future BMS PMU can display temperature and current measurements of each battery cells In addition the portability of the system could be increased with researching wireless capabilities The experiments are done with 24 lead acid battery cells However considering the MAX11068 specifications in future the system can be designed to be scalable up to 372 cells Nonetheless an alarming function could be added to the BMS PMU The complete BMS PMU can make use of the alarming function if any system parameters ex
63. ock Diagram The source part is consisted of charger step up DC DC converter and metal oxide semiconductor MOS switch The charger is selected so that the output of charger should be 12V 24V or 36V LTC3862 is placed at the output of charger which is a step up DC DC converter Linear Technology 2008 The output of LTC3802 is 48V with a current of 3A Two BUK654R0 75Cs are used as MOS switches The control part is consisted of gate drivers 24 cell lead acid batteries MAX11068 evaluation kit EVKit as a BMS Arduino Uno as a microcontroller and an optional 51 low dropout regulator LDO In addition Arduino Due can be replaced with Arduino Uno The major difference for this design is that Arduino Due s operating voltage is 3 3V Two IR2117s are planned to use as high side gate drivers and for level shifting purpose However there are some limitations to use them IR2117s have a bootstrap capacitor that pulls the logic supply voltage into gate node when it turns on The supply voltage charge in capacitor lasts for only couple milliseconds Next another pulse is needed for input pin Hence IR2117s can be only used with a 1 kHz pulse width modulation PWM signal Thus two IR2117s can be replaced in future High side gate driver configuration needs a switch between the load and supply The MOS gate is pulled high to turn on the high side gate driver With the usage of them the Arduino Uno can control the switches both on source and l
64. program are used in the PMU project The microcontroller is programmed so that it sends to and receives information from the Java program The GUI application is included to let users to investigate the voltage and SoC variations in whole battery module amp individual cells The users also have an option to write the data to Microsoft Office Excel sheet Therefore they can make use of it whenever they want The complete PMU system monitors the voltages and SoCs of whole battery module and individual cells accurately Moreover the GUI displays the changes the voltages and SoCs of whole battery module and individual cells on the SoC and voltage charts At the end of the project the theoretical knowledge is compared with experimental results ii PREFACE First and foremost I would like to thank my supervisor Professor Nikolay T Tchamov who gave me the opportunity to join the RF Integrated Circuits Laboratory and for his guidance advice encouragement and unwavering enthusiasm throughout my working time as research assistantship At many stages of this research project I have utilized from his experiences to explore new ideas I would thank to my examiner Jani J rvenhaara for spending his time to revise my MSc Thesis and for his precious comments to make my MSc Thesis well I also would like to thank my dear past and present group members in RF Integrated Circuits Laboratory for their friendship help and suggestions to accomplish my MS
65. rated 2012 Automotive Product Guide Accessed on 04 10 2013 Available at http digichip ru datasheet PDF 708f64cd8fd71531242118389f171796 6cc98ba2045fe40 98d24356d14447085 MAX2135AETNV pdf p 29 Maxim Integrated 2013 Evaluation System for the MAX11068 Accessed on 04 04 2013 Available at http www maximintegrated com datasheet index mvp id 6882 Maxim Integrated 2013 MAX17830 12 Channel High Voltage Battery Sensor with Advanced SMBus Ladder and External Cell Balancing Accessed on 04 10 2013 Available at http www maximintegrated com datasheet index mvp id 71 14 Miller P 2012 xEV market trend and prospect 2012 IEEE Vehicle Power and Propulsion Conference Seoul Korea National Geographic 2004 The End of Cheap Oil vol 205 no 6 NetBeans 2013 Welcome to the NetBeans Community Accessed on 09 05 2013 Available at https netbeans org about index html NXP Semiconductors UM10204 I2C bus specification and user manual Rev 5 9 October 2012 33 Pang S Farrell J Du J Barth M 2001 Battery State of Charge Estimation Proceedings of the American Control Conference vol 2 Pistoia G 2005 Batteries for Portable Devices Elsevier B V Amsterdam The Netherlands Pistoia G 2009 Battery Operated Devices and Systems First Edition Elsevier B V Amsterdam The Netherlands Racherla K 2011 Measure Multiple Temperatures in
66. rduino The Figure 15 shows the front view of Arduino Due The Arduino Due is connected to PC by micro USB cable When data is being transmitted between the PC and Arduino Due the receiver RX and transmitter TX light emitting diodes LEDs start to flash Arduino Figure 15 The front view of Arduino Due Arduino 28 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 The MAX11068 already includes the USB powered command module MINIQUSB together with the EVKit software The MINIQUSB provides the communication between the MAX11068 EVKit and PC Maxim Integrated 2008 However the MINIQUSB and EVKit software system is not modifiable and an improved version of visualization is required for user friendliness Therefore a new modifiable system is needed The Arduino Due is used in order to satisfy that need The Arduino Due is programmed based on the Maxim Integrated 2010 The MAX11068 EVKit becomes controllable with the Arduino Due In addition a new visual quality is provided via a Java graphical user interface GUI which is going to be discussed in Results and Discussion chapter The Arduino Due mainly controls measures and records the data Therefore the title of whole Battery PMU project is extended as Smart Battery PMU The microcontroller board interfaces with the battery packs via IC communications When the battery cells are charged off limits the microcontroller has a feature to switch off the charging process On the o
67. re 33 when the load is connected the load discharging curve of lead acid battery cell 19 with respect to time is given 0 8 0 6 Lead Acid Battery Cell 19 Voltage V 0 4 0 2 Figure 33 Load Discharging Curve of lead acid battery cell 19 Load Discharging Curve 0 20 40 60 80 100 Time mins 120 6 RESULTS AND DISCUSSION 47 From Figure 33 it is obtained the power delivered by cells with the inclined discharge curve drops during the discharge cycle The lead acid battery cell 19 voltage is 2 09V at the beginning After 116 minutes it is fallen to 1 68V The measurement is stopped when the least charged lead acid battery cell cell 19 is less than 1 7V Here 1 7V is the critical level that states the lead acid battery cell is fully discharged Enersys Cyclon 2008 In addition since the constant current load is used for the discharging process the 0 02A variation between the beginning and end is acceptable Furthermore the lead acid battery cells must be fully charged after every discharging process and they need to be kept charged at a floating voltage which is more than the nominal voltage 6 RESULTS AND DISCUSSION 48 After the discharging process and load is disconnected from the setup the battery cell voltages are also measured by the MS8221D multimeter Mastech 2013 The comparison between the GUI and multimeter measurements are given in Table
68. remotely operated devices and renewable energy systems generates high demand for fast propagation of battery technologies Bergveld et al 2002 This project is done because there are only limited applications of smart BMS or PMU which work with commercially available lead acid batteries The main goal of this MSc project is to design an accurate and safe PMU monitoring for a certain cell stack size including voltage and SoC measurements of battery module and individual cells for different charging conditions In 2011 various German automobile manufacturers proposed using 48V electrical system standard to obtain higher power than systems using 12V electrical system standard Miller 2012 This MSc Thesis which deals with 48V lead acid batteries is part of a larger KERS project Tampere University of Technology RF Integrated Circuits Laboratory 2013 that is going to provide energy interaction with DC DC converter and motor controller for mobile amp stationary big volume applications In this MSc Thesis the ways how a smart battery PMU can be designed for wide range of applications are researched The theoretical background is going to be given before explaining the PMU research methods and materials The PMU a modified version of BMS is going to be discussed The boards which can be used for designing PMU are going to be compared and the reason of selection of the MAX11068 EVKit is going to be explained Moreover the lead acid batteries are go
69. s are performed after that initial calculation results are applied in system prototype with minor modifications Later on system is designed with the Java software to control whole PMU system The proposed system for the smart battery PMU monitors the individual lead acid cell s performance using the microcontroller board Arduino Due The Arduino Due communicates with MAX11068 EVKit through an PC bus The Arduino Due provides communication for measurements of the voltages of each cell and based on those cell voltage measurements the SoCs are calculated by the Java program The Arduino Due commands are written based on Maxim Integrated 2010 Although this smart battery PMU is designed on a battery back of 24 lead acid cells the complete system can be used for a lead acid battery pack of any size up to 372 cells with minor modifications in the system The software allows users to make minor modifications for possible future requirements It is proved that the software is measuring lead acid cell voltages accurately with an error margin of 0 5 The 0 5 difference between the GUI and multimeter measurements is admissible To improve this Smart Battery PMU project the possible future design is discussed As a consequence this MSc Thesis is a part of major KERS project Tampere University of Technology RF Integrated Circuits Laboratory 2013 that is going to interact with the DC DC converter and motor controller for mobile or stationary high
70. st board Maxim Integrated MAX 11068 Evaluation System 2010 seen 21 Figure 15 The front view of Arduino Due Arduino eee 28 Figure 16 The complete measurement System 1 pine kaaa pda dd eade 32 Figure 17 Connection Setup of MAX11068 eese 32 Figure 18 Series connected Lead Acid battery design 0vaavvaa vana 33 Figure 19 Arduino Due amp J3 Header of MAX11068 Evaluation Kit PACK A Bonn ci P O GW Y A duc serene end i roba kai 33 Figure 20 bodddest on LL nee ede CG hei esed SAD 34 Figure 21 Complete system setup ssec eee iei edes ue tutae dg Sees Rd AC a vtt ex 35 Figure 22 The flowchart of programming of PMU esee 37 Figure 23 PMU GUI without charts ete GG FC Gyd WL re david teta ita 39 Figure 24 Individual cell voltages and SoCs iau aiiteton eet i entire ase 40 Figure 25 Total Battery SoC vs De aui aco ero puto late beton lila i 42 Figure 26 Total Battery SoC vs Time in a different period of time 42 Figure 27 Total Battery Voltage vs Time Rec oli ad beet 43 vi Figure 28 Total Battery Voltage vs Time in a different period of time 43 Figure 29 Instantaneous Battery Voltage SoC and Status sss 44 Figure 30 Cell voltages and measurement counter displayed in Excel sheet 44 Figure 31 Cell SoC and date amp time displayed in Excel
71. tage level across the battery terminals regardless of lead acid batteries SoC which are suitable for recharging lead acid batteries Moreover CC CV chargers ensure high preliminary current to the lead acid batteries due to the high voltage difference between the charger and lead acid batteries According to Enersys Cyclon 2008 constant voltage charging method is suggested for charging lead acid batteries when no current limit is required Therefore CC CV charging method should be applied when a current limit is required 2 3 2 1 Constant Current Constant Voltage Charging According to Linden et al 2002 modified constant potential with initial constant current charging method is the fastest and most effective way to recharge lead acid batteries In CC CV method a constant voltage with initial constant current is applied to battery to recharge it The charging current is at its peak at the beginning of charging process Moreover it is strongly suggested by Enersys Cyclon 2008 that the charging voltage has to be kept in the range of 2 45V to 2 5V per cell for cyclic applications If the 2 LITERATURE REVIEW 8 charging voltage is less than 2 45V per cell then there might happen a quick loss in cell capacity In Figure 5 changes in charge current in time are given for 2 5Ah battery charged by constant voltage of 2 45V Moreover chargers are limited to 0 3A IA and 2A Change in Charging Current vs time for a 2 5Ah battery charged by
72. tches the battery cells in and out of BMS Cell stack voltages NAN RYY R 23 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 3 2 1 Analog to Digital Converter ADC The MAX11068 can measure 12 cells A 12 bit ADC is utilized to digitize the cell voltages The MAX11068 measures each cell differentially The MAX11068 has a measurement range from 0 to 5V Maxim Integrated 2010 The output of ADC shows the cell measurement result The following equation is used to calculate the cell voltage ADC out x5 4096 In the equation above the 4096 comes from 2 since the maximum data bits are Cell Voltage equal to 12 In addition the ADC out is multiplied by 5 because the maximum cell voltage measurement could be equal to 5V 3 3 dumper Switch Configurations and Cell Connections Table 9 provides the complete shunt positions for the MAX11068 evaluation kit EV Kit The Tables 9 and 10 are done according to Maxim Integrated MAX11068 Evaluation System 2010 Table 9 Jumper Configurations based on number of cells of MAX11068 EVALUATION KIT PACKA amp B of Position of Shunt Cells JU2 JU3 JU4 JUS JUG JUT JU8 JU9 JU10 JUTI JU102 JU103 JU104 JU105 JU106 JU107 JU108 JU109 JU110 JU111 On On On On On On On On On On Off On On On On On On On On On Off Off On On On On On On On On Off Off Off On On On On On On On Off Off Off Off On On On On On On Off Off Off Off Off On On
73. th 2 5V voltage reference for gaining high accuracy Internal switch can be used to charge a cell slower than other cells if that cell has higher voltage than the other cells The whole MAX11068 is controlled by the 6MHz internal oscillator It determines the communication speed and ADC operations PC Upper Port master port is level shifted and referenced to ground GNDy 22 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 MAX11068 is a programmable battery monitoring data collection IC whereas MAX11080 is a battery pack fault monitor IC The MAX11068 monitor measures battery parameters voltage temperature State of Charge SoC State of Health SoH etc including the control loop It controls indirectly the charger and the load A monitor cannot interrupt the pack current Maxim Integrated 2010 The balancer maximizes the pack performance via providing cell balancing The balancer is sufficient for the BMS as long as it can control the charger and the load The MAX11080 IC only checks for under over voltage and temperature It cannot monitor the SoC or SoH The fault signal of the MAX11080 is not used in this MSc Thesis From Figure 13 the MAX11068 EVKit can be seen Figure 13 MAX11068 EVKit Maxim Integrated The numbers given in Figure 13 denotes that Arduino Connection Header Auxiliary Inputs Header that is connected to battery cells Cell configuration switch Ribbon cable that connect two MAX11068 EVKits Switch that swi
74. ther hand it can charge the weakest battery cell to provide cell balancing It can be designed to provide a long life PMU system Furthermore the maximum and minimum battery cell voltages are controlled simultaneously If the battery cell voltages drop below desired voltage level the microcontroller can be programmed to alarm the user via the GUI or a speaker mounted on the MAX11068 The Arduino Due has two FC interfaces which are SDA1 amp SCLI and SDA pin 20 amp SCL pin 21 The lowest MAX11068 device of SMBus ladder Board A communicates directly with Arduino Due command module The other MAX11068 devices in SMBus ladder are communicated with Arduino Due command module through the device below them via level shifted C communication bus In Table 16 the pin mapping of Arduino Due that used in smart battery PMU system can be found Arduino Table 16 Pin mapping of Arduino Due that used in system Pin Number Net Association 20 SDA 21 SCL 52 Digital Pin 52 53 Digital Pin 53 GND Ground 29 3 SYSTEM CONSIDERATIONS BASED ON MAX11068 3 6 In the Table 17 the EVKits or ICs that can be used for managing lead acid batteries are given The Table 17 is done according to Maxim Integrated Evaluation System for the MAX11068 2013 Maxim Integrated MAX17830 12 Channel High Voltage Battery Sensor with Advanced SMBus Ladder and External Cell Balancing 2013 Maxim Integrated MAX11068 12 Channel Acquis
75. tion of MOSFET Pp is given in the equation 13 It is calculated by multiplication of the drain current with potential difference of drain source Rs 12 Pp Via VBE on X Ip 13 Nonetheless a big value such as 10kQ is chosen for Rg so that the transistor is not damaged IRL2910 BC549B RS Q2 0 75 Figure 20 Load design This constant current load design has some advantages First the current can be kept stable independent of battery voltage Secondly the Rs dissipates low power since the potential difference across it is nearly 0 7V Consequently with the help of this constant current load the load discharging curve can be observed 34 4 POWER MANAGEMENT SYSTEM DESIGN 35 Lastly the complete system setup is illustrated in Figure 21 Figure 21 Complete system setup The numbers given in Figure 21 denotes that Cooling fan for the MOSFET Constant current load without sensing resistor MS8221D multimeter Mastech 2013 24 cells lead acid battery pack Sensing resistor Connection socket Arduino Due Two MAX11068 EVKits Di m Uv e mno In the complete system setup the multimeter is used for measuring the current passing through the load Also the connection sockets are connecting two MAX11068 EVKits to the 24 cells lead acid battery pack Also there are two connection sockets for each 12 lead acid battery cell for the series connected complete 24 cells lead acid battery setup
76. vide optimum use of battery powered devices by maximizing battery capacity and life reducing the risks of damaging those devices and controlling the charging voltage safely This can be accomplished by controlling i e cell balancing and or monitoring the charging and discharging processes of battery powered devices The monitor of PMU can measure and show the figures of merit of conditions of a battery which are voltage SoC State of Health SoH and temperature during charging and discharging based on the requirement of users However the monitor of PMU cannot directly impede the current In addition to those similar BMS functions PMU can alter the effective power supply source from batteries Wang et al 2010 PMU can provide low power consumption in system without affecting the system functions which separates it from BMS Consequently PMUs are connectors between batteries and battery operated devices systems which enhance battery performance and device system operation in a reliable and safe way In Figure 1 an example of usage of PMU is given 2 LITERATURE REVIEW 3 Cell Voltage amp SoC amp Temperature Monitoring Figure 1 General PMU Block Diagram In Figure 1 the load can be consisted of motor DC DC converters switches rectifiers power metal oxide semiconductor field effect transistors MOSFETs and pumps 2 1 2 Application Areas of PMU PMU has a wide range of applications from military to med

SELIMCAN DEDA SMART BATTERY POWER MANAGEMENT UNIT

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