OGYD2-EP - Protecta
Contents
1. 24 4 7 LED assignment and SW buttons 25 5 Construction external connections nasa 26 5 1 Drawings for a DTVA OGYD2 EP devitce 26 5 2 Drawings for a DTI OGYD2 EP devtce a 30 5 3 Drawings for an OGYD2 EP central unit a 34 54 Modules of the central Unit eisque 39 5 5 The front plate of the central unit and the large graphic display 40 6 Lechmeal data dio eo e Las nala IRS a sean Acme iat asta opc qu q toss ctp 46 Gob Specifica OBSS cae adole iu cena eee ie ots 46 6 2 Setting TAN GES Een RN PRENNE OSEE UT 47 Nar 48 To APE ST AMA IBIODH GU DIE as haan elas Gaol dius pas obe ass 50 Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 2 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd HE 1 Field of application The bus bars play an important role in the high voltage electric power system Since the bus bar concentrates the short circuit power destructive effects caused by a fault by a d2. Rated secondary current I lAor5 Rated secondary line voltage Un 100 V or 200 V Rated frequency 50 Hz Overload capacity in voltage circuits continuous 1 2xUn Overload capacity in current circuits continuous 4xI ls 100xI Dynamic current limit 100 1 Minimum time to saturation demand tr gt 1ms Accuracy of digital timer 3 ms at 10 ms steps 12 ms at Is steps Optical coupler inputs central unit 8 16 pcs Output relays central unit 16 pcs print relays Output contacts ratings central unit rated switching voltage 250 V continuous load current 8A switching on current 16A In signal circuits breaking current at 220 V DC pure conductive circuit 0 25 A L R 40 ms load 0 2A In trip circuits L R 40 ms load 4A Busbar protection operating time 2 x Id basic sensitivity 30 ms 5 x Id basic sensitivity 25 ms 50 x Id basic sensitivity 20 ms Consumption basic device 80 mA 220 V for each 3 feeder each COM3 board 36 mA 220 V for each digital input 4 mA 220 V Auxiliary dc battery voltage the same supply unit 220 V 110 V voltage tolerance 88 to 310 V Permissive ambient temperature 0 to 50 C Insulation test 255 2 kV 50 Hz 5 kV 1 2 50 us Disturbance test IEC 255 2 5 kV 1 MHz Electrostatic discharge test ESD IEC 801 2 8 kV Burst test IEC 801 4 2kV Elect
3. PROTEC OGYD2 EP User s manual lectronics Co Ltd 5 5 3 The status window The status window displays the actual state of the individual bays The energised state the load current the breaker failure status and the healthy connection to the central unit via fibre optic cable are displayed here if the breaker failure signal is in case of communication error if R phase current gt 10 Bay name w if R phase voltage 1096 Status Ur Ir H8i 0Xh Bay Status of the bay in hex format ompiled by Approved by Date Page y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 44 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd In the bus bar configuration window when pressing the arrow push button to the right of the service icon the list of the bays is displayed with disconnecor states and additional information Pressing the TEST arrow the information is displayed to support commissioning The bus bar is displayed in this case independently of the disconnector states containing only one assigned measuring element The bays can be connected one by one independently of the disconnector states The connected bays are marked with a check mark V indicating that the current of the bay is involved in the calculation of the biasing current This function supports checking the correct polarity con
4. LED Explanation 1 LCD Warning LED indicates message on the display parameter changes or need of acknowledgement 2 AI Differential protection function operated 3 Disconn Disconnector status signal error 4 Line error Fiber optic connection error 5 BF disable Breaker failure protection disabled by parameter setting 6 BB disable Bus bar diff protection disabled by parameter setting 7 Test Test state as set by parameter SW switches Explanation SW2 upper No assignment in this configuration SWI lower Acknowledgement valid for the bay units too Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 25 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd 5 Construction external connections The construction and external connections of the OGYD2 EP bus bar differential protection and breaker failure protection are explained in Figures 6 15 Figures 6 11 show the connections of the bay unit Fig 12 15 show those of the central unit 5 1 Drawings for a DTVA OGYD2 EP device Fig 6 shows the external connections of a combined DTVA OGYD2 EP device distance protection and automatic recloser combined with the bay unit of the bus bar protection important from the OGYD2 EP functionality Some connections are common with the functions of the DTVA functions
5. command for the bus bar section The subtracted a IOffset value is parameter setting the proposed value of it is the expected maximum load current value of each bay currents and will be common for all bays The consequence of this setting is that independently of the number of the bays and independently of the actual load in normal operation the biasing K s value is constant zero This is because the summation contains elements only for which gt In case of internal bus bar faults the maximal trip speed is realized the optimal trip time can be 8 ms The trip characteristic for a measuring element is shown in Fig 1 ompiled by Approved by Date Page p y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 8 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd Id trip In K 0 8 80 10 K 0 5 50 5 I base setting Is bias 0 IOffset 10 15 20 In Fig l The trip characteristic for a measuring element For an internal bus bar fault the measuring principle described above can be seen in Fig 2 Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 9 50 PROTEC OGYD2 EP User s manual lectronics Co Ltd Fig 2 Measurement of internal bus bar fault The top of Fig 2 shows a simple bus bar section configuration Suppl
6. Timer start Timer timeout 10 ms timer start 10 ms timer timeout O 9 16 00 O 17 24 00 O 25 32 00 0000 0000 0000 00 00 Timers for each measuring element CT error timer start CT error timer drop off VT timer BF timer oooo 4 6 Inputs and outputs of the PROTLOG equations Inputs source variables INPUT VARIABLE Explanation O5 08 State of optically isolated inputs 5 8 BB operated Bus bar protection operated BF operated Breaker failure protection operated CT error Current transformer circuit error MI Mm trip Measuring element 1 m trip command Disc status error timeout Disconector status error timeout OX error OXO fiber optic connection error Disc status error Disconnector status error SW ackn Acknowledgement with SW1 push button All input variables are repeated with where means latched signal Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 24 50 PROTECTA Electronics Co Ltd OGYD2 EP User s manual U Outputs OUTPUT VARIABLE Explanation R13 R16 Operation of output relay 13 16 BB prot disable Bus bar protection disable BF prot disable Breaker failure protection disable Ackn Acknowledgement 4 7 LED assignment and SW buttons
7. only if the currents are outside the tripping zone of the characteristics A voltage monitoring function can allow trip command only for 5 s then the function is disabled until the measured voltage returns to healthy state again or a new initializing is performed caused by disconnector status change switching on parameter changes If all voltage monitoring functions assigned to a measuring element detect low voltage then the bus bar section is considered to be disconnected and the operation of the bus bar differential protection is enabled again to cover the switch on to fault condition If the trip command is disabled by the voltage condition then the On line screen of the connected PC displays the status signal as U gt disable If one or more voltage supervisions detect low voltage then the display changes form to At that moment a 5 s timer is started and when it expires then the operated voltage supervision function is disabled As a consequence the signal shows again 3 1 3 Supervising the current transformer circuits Each measuring element supervises he current transformers the bay of which is connected to the bus bar section The central unit measures with each measuring element in all three phases the current differences If the differential current value in any phases is above the current error setting Iset CT error but the associated voltage is healthy U gt block then a timer is start
8. or checks the protection can be set to test mode In this case no trip commands are generated The parameter to be set is Test The parameter value is to be changed to to set the device in test mode ompiled by Approved by Date Page y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 20 50 PROTECTA Electronics Co Ltd OGYD2 EP User s manual 4 Information from and to OGYD2 EP bus bar differential and breaker failure protection 4 1 Parameter setting and setting ranges Setting of the differential characteristics primary current values NAME DIM RANGE STEP Explanation I base setting A 50 5000 10 Differential characteristics current base setting Biasing 90 50 80 5 Slope of the characteristic I Offset A 0 5000 10 Expected maximal bay load current Iset CT error A 10 5000 25 CT current error setting Bay setting data as stored in the central unit primary CT rated current values NAME DIM RANGE STEP FIX DISCONNECTED In l bay name CT Pr 50 5000 25 In 2 bay CTPr A 50 5000 25 Inin bay CT Pr A 50 5000 25 The bay is considered to be permanently disconnected if the setting is Timer parameters NAME DIM RANGE STEP Explanation C
9. s manual gj Cute L ulz Fig 11 Rear view of a DTI OGYD2 EP device Compiled by Approved by Date Page L szl Eperjesi 14 09 2004 33 50 Ferenc Radvanszki and Gyula P ka PROTEC A OGYD2 EP User s manual lectronics Co Ltd If the protected bus bar can be divided into sections by bus disconnectors then the status signals of these disconnectors are input to the central unit In case of bay structure a dedicated device can be assigned to the disconnector bay and this device can be connected via high speed fiber optic cable to the central unit This bay unit can include all necessary modules power supply unit central CPU unit OXO fiber optic cable driver unit As an example the dedicated disconnector unit may connect the signal circuits according to Fig 12 The realization depends on the substation configuration and PROTECTA Co Ltd delivers the actual connection diagrams with the OGYD2 EP devices BUS BAR DISCONNECTOR S KI 1 ON S IDEE 57 BUS kK 2 tus 3 ON N C r BUS B eK 4 OFF Fig 12 Connection of a bus bar disconnector configuration 5 3 Drawings for an OGYD2 EP central unit The central unit of the OGYD2 EP bus bar protection system is a fully numerical d
10. some current samples are missing as caused by the distortion of the saturation The Fig 3 shows Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 12 50 E PROTEC A OGYD2 EP User s manual lectronics Co Ltd ideal saturation In calculation of dp this missing current section is detected dashed line The third section of Fig 3 shows the calculated Isp dashed line too It is clearly seen that the biasing current increases immediately and because of the saturation the increasing is slowed down only at the end of the first half period Of course in the first half period the values are halved as in case of internal fault As the fourth section of Fig 3 shows the summed 5 biasing current is continuously above Id So in case of K 0 8 the comparison performed in each millisecond never cause operation of the differential protection function Based on Fig 3 the limits of the measuring principle of OGYD2 can be explained Let s suppose that the current transformer of the faulty bay saturates at current and that the current transformer can not deliver secondary current in saturated state ideal saturation If the sum of the currents on healthy bays is zm this is the maximal fault current when the protection operates correctly in the faulty bay it is only Zr less than the fault current then the t
11. transmitted to the CPU OGYD module This line error signal disables trip command 3 2 Digital breaker failure protection 3 2 1 Method of operation The operation of the digital breaker failure protection integrated in the OGYD2 EP device is as follows A breaker failure protection function is assigned to each measuring element In the supervision only those bays are included which are connected to the bus bar section All bay units collect breaker failure start commands from the bay oriented protection functions and checks if current is flowing in the bay and supervises if really trip command is sent to any of the circuit breaker trip coils of the bay If all conditions are fulfilled then without any time delay the bay unit sends a message to the central unit with the content that the possible state is breaker failure The starting conditions for breaker failure protection starting are as follows a In a transformer bay no current supervision is involved BFstart RTriplI RTripII STripl A STripII TKil T TripII b In a bay without transformer the current is checked as well BFstart RTripI RTripI1 Ir STripI STripI1 Is TKil TTripI1 It ompiled by Approved by Date Page p y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 19 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd In these conditions BFstart the bay unit detected breaker failur
12. 2 4 Communication e 2x16 character LCD display for setting the functions displaying messages and reading recorded events on line screen on external PC to make setting commissioning and testing easier external communication interface can be set for RS 232 or for fibre optic cable optional interface module for SCADA systems the parameters can be saved and downloaded real time clock handling with the help of RAM with battery which can be synchronised via optical fibre cable connected to external PC or to the SCADA system Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 5 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd 3 Working principle The OGYD2 EP numerical protection integrates two independent protection functions numerical differential protection breaker failure protection 3 1 Numerical bus bar differential protection 3 1 1 Method of operation The numerical bus bar differential protection system consists of a central unit and individually one bay unit for each bays The structure of the system can be centralized where the central unit and the bay units are mounted in a cabinet or it can be decentralized bay oriented when the central unit is mounted in a central cabinet and the bay units are located near to the bays The bay unit can be an EuroProt type distance protection or overcurrent protection which i
13. External communication mode Opto RS 0 1 optical fiber cable RS 232 Optical fiber cable operation method 1 1 loop 0 radial Series communication speed BaudRate 150 to 19200 Baud with 2x steps Substation code 0 to 254 Device code 0 to 254 Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 47 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd 6 3 Size An EuroProt device is always of rack mounted type One of the design forms is suitable to be mounted directly into a standard 19 inch cabinet frame The other designs are panel mounted devices with raised hinged or flush mounted forms The central unit of the OGYD2 EP bus bar protection and breaker failure protection Outline size of a 19 inch cabinet frame mounted device and that of a panel mounted device with flush mounted form is as follows Width 483 mm height 132 5 mm depth 201 mm Outline size of a panel mounted device with raised hinged form is as follows Width 490 mm height with terminals 250 mm depth 250 mm The feeder unit of the OGYD2 EP bus bar protection and breaker failure protection It is a printed circuit board plugged into the EuroProt protection The size of the device can be the same as that of the central unit but it can be smaller as follows Outline size of a 19 inch cabinet frame
14. P424 4731 Four output relays K13 K14 K15 K16 G R4 EU RELAY P424 4758 Four output relays K9 K10 K11 K12 RAE EU RELAY P424 4731 Four output relays K5 K6 K7 K8 1 RAJEU RELAY P424 4758 Four output relays K2 J CPU MAIN EU 198A P436 7069 Central unit with the main processor memories I O divers serial input output communication optical fiber cable connector with its driver integrated program monitoring with Watch Dog event memory for 50 events event sequence recorder for 300 events with 1 ms resolution K CPU DSP EU 196A P352 5613 Digital signal processor for the differential protection central function CPU OGYD Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 39 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd L COM3 EU MULTICOM3 P479 COM3 board for three feeders or independent disconnecor switches e g sectionalisers in order to receive the optical fiber cable pairs COM3 EU MULTICOM3 P479 COM3 board for three feeders or independent disconnector switches e g sectionalisers in order to receive the optical fiber cable pairs N COM3 EU MULTICOM3 P479 COM3 board for three feeders or independent disconnector switches e g sectionalisers in order to receive the optical fiber cable pairs COM3 EU MULTICOM3 P479 COM3 board for three feeders or inde
15. T error delay ms 100 32000 10 Timer setting for CT error signaling BF timer 1 ms 0 32000 10 Breaker failure timer 1 BF timer 2 ms 0 32000 10 Breaker failure timer 2 Disc status error timer 5 1 60 1 Disconnector status error time delay Voltage condition parameter NAME Value Explanation Bay voltage condition 0 7 Un Fix setting Logic parameters NAME Explanation Bay fix disconnected Bay fix disconnected Bus bar diff prot disable Bus bar differential protection disable BF protection disable Breaker failure protection disable Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 21 50 PROTEC lectronics Co Ltd OGYD2 EP User s manual Communication parameters NAME Explanation Opto RS 0 1 Selection of serial port fiber optic connector or RS232 FiberOpticLoop 1 Yes 1 operation in loop 0 radial connection BaudRate Setting range 150 19200 Baud step 2 Device Code Device identifier setting range 0 254 Station Code Station identifier setting range 0 254 4 2 List of evaluated events NAME Explanation Protection start yy mm dd hh mm ss ms Protection reset yy mm dd hh mm ss ms BB diff prot operation Bus bar differential protection operated BF prot operation Break
16. be calculated as shown below supposing ideal saturation t pesci T o Izm I The maximal current at which the current transmission of the current transformer is distortion less which means that the current value at the moment of tr related to the F 21 15 I sin ar In T The relations of these last two equations are shown in Fig 4 a In case of a bus bar with high short circuit power the current transformer in the faulty bay can be extremely saturated Fig 4 b shows two cases supposing ideal saturation In one case the time to saturation is 2 ms in the other one it is 3 ms Based on the equations above the data are I I for 22 5 tr 3 ms 4 I I for 22 10 tr 2 ms and 6 I T Tcs Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 14 50 PROTEC OGYD2 EP User s manual lectronics Co Ltd xlr Fig 4 a Time to saturation and the maximal transmitted current as the function of the fault curent 1 I i I 1 I 3 M HR N o r ore Fig 4 b External fault causing extreme saturation supposing ideal saturation ompiled by Approved by Date Page p y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 15 50 PROTEC TA OGYD2 EP User s manual lect
17. ble configurations The first underlined italic letter is the location in the rack The second underlined bold name is the identifier of the module as the rear lever of the module shows The brackets contain the identifier of the printed circuit board then the bold underlined number is the factory identifier A T EU TAP 2A P368 3843 This is the power supply unit of the OGYD2 EP device with DC DC converter The same power supply unit can be connected to 110 V or 220 V substation battery voltage since the unit has extreme high voltage tolerance it extends from 88 V to 310 V Additionally the input is polarity protected There is a digital optical coupler input in the board for clock synchronization B EU TAST P369 4 4732 or 5629 This module can not be seen in the ready mounted state of the device this is why it does not have handle identifier This module is located behind the front plate of the device it can be accessed after removing the front plate The board serves man machine interface of the front plate the keyboard the connector for serial communication the LED s etc Both the front plate from the front side and the printed circuit boards of the other modules from rear side are plugged to this plate C O EU OPTO P354 4733 Eight optically isolated binary inputs D O EU OPTO P354 4733 Eight optically isolated binary inputs O EU OPTO P354 4733 Eight optically isolated binary inputs F R4 EU RELAY
18. ce protection or an overcurrent protection which is extended by a bay module all bay units are interconnected with the central unit via high speed serial fiber optic cable pair the bay units send to the central unit the following information o the current values of each phases sampled synchronized with 1 ms time steps o presence or absence of the three phase voltages o the status of bus disconnectors of the bay using two bit status signals o starting command for the bay breaker failure protection o signal of the trip command for the circuit breaker in the individual phases the central unit is of numerical type operating with a main processor CPU main and separated digital signal processor CPU OGYD the central unit sends to the bay units the following information o synchronizing signal with 1 ms time steps o trip command if needed all currents and binary signals are of three phase information the central unit determines the bus bar configuration based on the signals received via fiber optic cable and assigns measuring elements to the independent bus sections the measuring elements build the sum of the currents current difference and calculate the biasing current based on the current magnitudes the decision of the measuring elements is based on the characteristics with a single knee point because of the special decision logic the operation is safe even in case of high grade of CT saturation to issue the trip command the v
19. e erem 73 _ wom Fig 6 Connections serving the OGYD2 EP functions of a bay unit of DTVA OGYD2 EP type ompiled by Approved by Date Page y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 27 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd r IU 0 S6 ua RE is TRIP ILR 1 RIPLTT lt Denomination SELF TEST SELF TEST K10 AUT DISABL AS AS s E Denomination n E EEEBB t a 8 N _ N NJN o i Denomination 6 METTETE AR start puo 2 R ON status 54 3 3 S ON status 55 Input 15 Input 16 OPTO 1 8 Dl nj 7 oo D 1 Bus OFF Bus ON 3 Bus K OFF 62 Fig 7 Complete list of connections of a DTVA OGYD2 EP device Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 28 50 PROTEC lectronics Co Ltd OGYD2 EP User s manual R4El 05 R4l 06 R4E 01 R4 02 R4E 01 0 2201 0 2201 0 2201 54 2202 ka No vwx gt Fig 8 Rear view of aDTVA OGYD2 EP dev
20. e g current and voltage inputs power supply trip command etc others serve the bus bar functions only e g disconnector status signals fiber optic inputs for the trip commands This Figure does not show the two fiber optic connectors for the laser driver OXO module Fig 7 is the complete list of connections of a DTVA OGYD2 EP device distance protection and automatic recloser combined with the bay unit of the bus bar protection Fig 8 is the rear view of a DTVA OGYD2 EP device indicating the module identifiers positions and connectors ompiled by Approved by Date Page y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 26 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd BAY CONNECTION 02 lt 2 gt 03 i 5 3 L a 4 5 4 0 6 m Up 7 p Us 8 M Ur I 9 Mi b r3 o LR x 0 11 TRIP LS b Loo 12 gt TRIP LT J 13 ON 14 15 lt MIl x te 16 M ILR t9 17 TRIP 1 5 v 18 gt TRIP ILT 21 Lo 22 SELF TEST 23 lt M 24 AUT DISABLED 65 BF START L J 61 ON aus Kk MEC 62 OFF J 63 ON aus B et _H 64 OFF ee eo 70 CLOCK SYNCH LH n Cie E
21. e start external signal in the dedicated optically isolated digital inputs RTripl RTripll the bay unit detected trip command as sent to the indicated phase and indicated trip coil in the dedicated optically isolated digital inputs Ir Is It the OXO modules in the bay unit measured the current in the indicated phase and generated permission because the measured current value is above 0 1 In bay The central unit receives the messages as generated in the bay units according to the conditions above and starts the tl and t2 timers The time delays are set by parameters BF timer 1 BF timer2 In case of timeout of tl a command is sent to the selected bay unit to generate a new trip command to both trip coils of the circuit breaker the duration of the command is 500 ms If this command has no effect and the conditions are permanently fulfilled then after t2 time delay all circuit breakers connected to the bus bar section receive the trip command the duration of the command is 500 ms here too The breaker failure protection supervises the individual phases but generates a three phase trip command The breaker failure protection function can be disabled using an output of the PROTLOG equation BF prot disable The parameter BF protection disable disables the function permanently In this case the LED BF disabled indicates the disabled state and the PROTLOG equation has no further effect 3 3 Test mode For the time of commissioning
22. ectronics Co Ltd 7 Ordering information On ordering the OGYD2 EP bus bar protection and breaker failure protection the following data have to be given the DC supply voltage value the primary disposition of the protected bus bar with CB s disconnecor switches location of the measuring transformers maximum fault current minimum CT primary rated current and the related accuracy limit factor of CT s the requested design of the bus bar protection centralized decentralized mounting version form of the protection On ordering it is advised to consult with the experts of PROTECTA Electronics Co Ltd Compiled by Approved by Date Page Ferenc Radv nszki and Gyula P ka L szl Eperjesi 14 09 2004 50 50
23. ed CT error delay If this timer expires CT error signal is generated and the trip command is blocked The condition to start the timer is U block Idr gt Iset CT error Ids gt Iset CT error Idt gt Iset CT error Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 18 50 PROTEC OGYD2 EP User s manual lectronics Co Ltd The CT error state is considered to reset if the differential current is below the current error setting in all three phases Idr lt Iset CT error Ids lt Iset CT error Idt Iset CT error If the conditions are fulfilled then after a drop off delay the status is reset and the protection is operable again The drop of delay timer and the start delay timer operate with the same parameter setting CT error delay During normal operation of the power system there is no possibility to set the CT error state If however the protection is tested in the laboratory or current is injected into the device care must be taken because the CT error state after the time delay disables trip command 3 1 4 Fiber optic cable supervision Additionally to the data communication the COM3 modules inserted in the central unit have the important task to supervise the healthy state of the fiber optic cable lines A precise integrating algorithm is applied to recognize the line error within 3 ms The signal of the error state is
24. ential protection function is performed by the CPU OGYD module alone the data exchange between the MAIN and OGYD is limited to the status signal connected to the central unit and to the signals indicating the operations ompiled by Approved by Date Page y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 6 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd The bay units send the status signals with two bits on and off state of the bay disconnectors in each milliseconds via high speed fiber optic connection to the central unit Additionally the bay unit sends the information about the presence or absence of the voltages in all three phases the commands submitted to the bay circuit breakers and breaker failure information received by the bay unit from external sources or generated by the own breaker failure function Following the device energizing and after each parameter modifications all disconnectors are supposed to be disconnected If there are no changes in the status signals in the subsequent 10 ms then based on the received signals the OGYD2 performs configuration which means determination of the bus bar lay out in the substation and assigns measuring elements to each separated bus sections This process is performed after each changes in the status of all disconnectors so after 10 ms the protection adapts itself to the new configuration and the meas
25. er failure protection operated Trip bay 1 Trip command to bay 1 Trip bay 2 Trip command to bay 2 Trip bay n Trip command to bay n 4 3 List of digital events NAME Explanation Test state Commissioning state BB diff prot disabled Disabled state of the bus bar differential protection function BF prot disabled Disabled state of the breaker failure protection function OX error OXO fiber optic driver or fiber optic connection error Disconn error Disconnector status signal discrepancy Bay 1 trip Bay is disconnected by the protection Bay 2 trip Bay 2 is disconnected by the protection Bay n trip Bayn is disconnected by the protection For each measuring element MI trip R Trip command of the measuring element 1 in phase R MI trip S Trip command of the measuring element 1 in phase S MI trip T Trip command of the measuring element 1 in phase T MI BF prot start Measuring element 1 breaker failure protection start MI BF prot trip Measuring element 1 breaker failure protection trip command MI CT circuit error Measuring element 1 current transformer circuit error MI VT OK Measuring element 1 voltage transformer OK or permanently neglected Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 22 50 PROTEC A OGYD2 EP User s manual Electro
26. evice failure by a handling mistake or by any other reasons are very high A high speed bus bar protection with high reliability can decrease the damage The OGYD2 EP type three phase biased bus bar differential protection and circuit breaker failure protection based on optical fibre cable links developed by PROTECTA Electronics Co Ltd can be used for this aim Information currents voltages status indications trips from the bay units are sent to the central unit via high speed series lines of optical fibre cable The central unit performs bus section selective protection with independent measuring relays assigned to the actual bus bar configuration The central unit evaluates the information and detects bus bar faults and the failure of a breaker and generates backup trip command if it is necessary Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 3 50 E PROTEC A OGYD2 EP User s manual lectronics Co Ltd 2 Main characteristics The devices of the OGYD2 EP bus bar differential protection and circuit breaker failure protection system are members of the EuroProt device family made by PROTECTA Electronics Co Ltd The main characteristics concerning the operation of the bus bar protection system are as follows 2 1 Functional characteristics one central unit one bay unit for each bays the bay unit can be an EuroProt type distan
27. evice with main processor additional signal processors and fiber optic input units for three fiber optic cable pair connections each The main connections of a central unit are drawn in Fig 13 ompiled by Approved by Date Page p y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 34 50 lectronics Co Ltd PROTEC A OGYD2 EP User s manual CENTRAL CONNECTIO as oe o 2 M1 o oo 3 2 o 4 M3 amp o 5 4 6 o oo 7 o o 8 MZ o 9 M27 oo o M3Z Loo 1 M4Z 12 gt SELF TEST 3 BF OPER CLOCK SYNCH 2 HA 5 ie POWER SUPPLY DC IZ it X K 8 ON N DISC 1 TEES 19 OFF L f S MEUS e MES 20 ON DISC 2 ek 21 OFF HH 22 ON M hoise s 5 OFF ta 24 ON EN DISC 4 qHH 25 OFF 26 Fig 13 Connections of the OGYD2 EP central unit Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 35 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd Fig 14 is the complete list of connections of an OGYD2 EP central device Fig 15 is the rear view of an OGYD2 EP central device indicating the module iden
28. f the current directions in the bays and the checking of the trip commands is possible as well The TEST state supports commissioning In this case the bus bar is considered to be a single protected unit independently of the state of the disconnect switches The bays can be included into the protected system one by one by pressing the ON push button in the Test ompiled by Approved by Date Page p y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 42 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd column selected with the navigation arrows In the row of the activated bays a checkmark signals the active status meaning the participation in the delta and sum currents This function supports checking the correct direction of the currents in the bays and independently of the current values no trip command is generated in the test state To check the operation of the trip command the OFF push button has to be activated after finding the appropriate bay C B Trip field with the navigation arrows Disconnect switch in C B Trip the bay column Test Name of the ba d Cursor navigation push button ON OFF buttons Ee NN L2 L3 Pee NEN L2 L3 Current sum Switch over to the status window Delta current ompiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 43 50
29. h high reliability As the result of the application of the methods explained above the operation of the protection is reliable in case of extreme stationary saturation and for high residual flux value as well The only requirement of the protection is tr21 ms minimal time to saturation the time span when the current transition is distortion less The bus bar differential protection measures in all three phases but the trip command is generated common for all three phases of the circuit breaker Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 17 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd 3 1 2 Voltage breakdown condition The trip command is released only if in the affected bay and in the affected phase the voltage collapses To perform this supervision all bay units monitor the presence of the voltage with a quick voltage measuring function The result of the supervision is sent to the CPU OGYD in every milliseconds If the voltage is below 0 7Un the function drops If any of the voltage functions signals low voltage then the operation of the assigned measuring element is enabled and if the currents fulfill the differential criteria the algorithm generates a trip command If the differential protection function started and the bay units received trip command then this voltage condition does not play any role The trip command resets
30. ice ompiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 29 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd 5 2 Drawings for a DTI OGYD2 EP device Fig 9 shows the external connections of a combined DTI OGYD2 EP device overcurrent protection combined with the bay unit of the bus bar protection important from the OGYD2 EP functionality Some connections are common with the functions of the DTT functions e g current and voltage inputs power supply trip command etc others serve the bus bar functions only e g disconnector status signals fiber optic inputs for the trip commands This Figure does not show the two fiber optic connectors for the laser driver OXO module Fig 10 is the complete list of connections of a DTI OGYD2 EP device overcurrent protection combined with the bay unit of the bus bar protection Fig 11 is the rear view of a DTI OGYD2 EP device indicating the module identifiers positions and connectors Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 30 50 OGYD2 EP User s manual PROTEC lectronics Co Ltd m BAY CONNECTION X r3 oo 10 TRP to 9 11 gt TRIP 1 5 Ls eA oo 12 LT pas 14 AUT DISABLE r
31. l fault because the 25 times checking can occur only for external faults The only exception is the transition of the fault location when a close external fault evolves to internal fault In this special case the operation can be expected only after a 25 ms time delay but this method increases stability for external faults To avoid false tripping OGYD2 EP applies another safety method too All bay units of the bus bar differential protection system monitor in all three phases the increasing and decreasing periods of the bay currents If in a bay the current increases subsequently decreases within 3 ms then the protection algorithm keeps the last high value up to the end of the half period This method supplies at least partly the missing current samples and at the same time no excess in biasing current can occur because this curve shape results the same current value as the unsaturated one if the time span is 2 ms and about the half value if the time span is 1 ms See Fig 4 b This method results suitable biasing and a small d value which assures stability for stationary external faults even in case of 40 times saturation current e g for nz10 this means 10 40 400 times rated current This explanation proves the use of the method keeping the last high value up to the end of the half period It has to be mentioned that even in extreme cases the method of changing the number of checking from 8 to 25 can prevent false tripping wit
32. mentary current values a predetermined with parameter setting load vale is subtracted d p T here a IOffset parameter setting the proposed value of it is the expected maximum load current value of each bay currents Out of these differences the values above 0 if a gt 0 are summed Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 7 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd L DAt 4 then the average of this value and that received 10 ms before is calculated I I sp s p l0ms spl 2 the same procedure is repeated with the subsequent sampled value and with the value sampled by 10 ms before that and the procedure is repeated ten times These ten calculated values are averaged receiving the Zs biasing current 10 n l 10 The biasing is calculated by multiplying the s biasing current by a biasing factor parameter Biasing which can be set in the range 50 80 2 0 5 0 8 10 K Is S 10 Is The bus bar differential protection operates if Id K Is and Id gt Id base The measuring element assigned to the bus bar section shifts the ten point window of the procedures by 1 ms and the procedure is repeated 8 times If all steps result trip condition which means that the trip condition lasts for 8 ms the measuring element generates trip
33. mounted device and a panel mounted device with flush mounted form is as follows Width 483 mm height 132 5 mm depth 201 mm The width of the panel mounted device in flush mounted form can be smaller than the size above A panel mounted device with raised hinged form has three different versions as follows Size with terminals Maximum outline size Width 490 mm height 250 mm depth 250 mm Medium outline size Width 384 mm height 250 mm depth 250 mm Minimum outline size Width 277 mm height 250 mm depth 250 mm ompiled by Approved by Date Page p y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 48 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd Without terminals and fittings for raised hinged form Maximum outline size Width 490 mm height 132 5 mm depth 201 mm Medium outline size Width 384 mm height 132 5 mm depth 201 mm Minimum outline size Width 277 mm height 132 5 mm depth 201 mm Terminal type at panel mounted design is as follows terminals are placed only below the device Switchable WTL6 1 Weidm ller Not switchable WDU 2 5 Weidmiiller Weight of the central unit of the protection is 8 kg ompiled by Approved by Date Page y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 49 50 E PROTEC A OGYD2 EP User s manual l
34. nection of the current transformers and independently of the current magnitude no trip command is generated For easy checking the a value IOffset is not subtracted from the measured currents This method is useful in commissioning and checking In this TEST state trip command can be generated which are then performed by the bay units The individual bays can be disabled one by one with parameter setting On the PC s Parameter screen it means writing a character for the Bay fix disconnected parameter The disabled state is indicated on the display of the device with a wrench symbol In this state the central unit considers the bay independently of the state of the disconnector to be disconnected the current is reset to zero and the voltage is supposed to be healthy All functions operate with these substituted information The fix disconnection of the bay is useful if the bay is disconnected for maintenance The role of the arrow pushbuttons to the right of the display is indicated by software icons on the screen The actual configuration of the display is described individually attached to the bus bar protection device Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 45 50 PROTECTA Electronics Co Ltd OGYD2 EP User s manual 6 Technical data valid both for the central unit and for the bay units 6 1 Specification
35. nics Co Ltd 4 4 List of LCD messages MESSAGE Explanation DSP error Digital signal processor error BB diff prot trip Bus bar differential protection generated trip command prot trip Breaker failure protection generated trip command CT circuit error Current transformer circuit error 4 5 On line information The On line screen is displayed on a connected PC running Protect for Windows operating software under Windows environment See EuroProt complex protection hardware and software description and user s manual The measured current values are displayed in primary Ampers The bay currents are approximate values based on rectified average measurement Information for each measuring elements Measuring element 1 Delta Summa Idr OA Isr OA Ids OA Iss OA Idt OA Ist OA Trip R Trip S Trip T BE start BF trip CT error U gt block Bay information 1 bay current 123 Trip 2 bay name current 123 Trip n bay name current 123 Trip Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 23 50 PROTECTA Electronics Co Ltd OGYD2 EP User s manual Common information Test state BB prot disabled BF prot disabled Opto error Disconn error Service information O 1 8 200 Internal variables 1 16
36. oltage breakdown condition must be fulfilled as well operating time is below 20 ms see section 7 Technical data in detail The breaker failure protection has two steps the first step generates a new trip command to the own circuit breaker the second step issues general trip command to all circuit breakers Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 4 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd 2 2 Software characteristics e integrated self check functions e digital event recorder for 50 events and an event sequence recorder with 1 ms time resolution for maximum 300 events e analogue event records with current data 2 3 Hardware characteristics e numerical type with own A D converter digital signal processor DSP and separate main processor e the system can be structured in two versions e centralized structure when the central unit and the bay units are mounted in a cabinet e decentralized bay oriented structure when the central unit is mounted in a central cabinet the bay units are located near to the individual bays e opto coupler inputs e output contacts e the type of the contacts NC or NO can be selected individually for each contacts when ordering e versions for 19 rack cabinet mounting or housed in relay case semi flush mounting or hinged type optional DIGIPROT fault recorder board
37. ompiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 40 50 PROTEC lectronics Co Ltd OGYD2 EP User s manual Fig 16 Front view of the central unit Compiled by Approved by Date Page Ferenc Radv nszki and Gyula P ka L szl Eperjesi 14 09 2004 41 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd 5 5 1 Displaying the bus bar configuration If normal operation the graphical LCD displays the single line scheme of the bus bar and shows the status information of the disconnect switches and the measured current values Bay name Ir Phase R Bayi Bay2 Bay3 Bay 4 current of the bay Disconnect switch status Closed X Status error 1 1 x Status error 0 0 Bay is disabled Switch to the protection service excludes this bay window 5 5 2 Service window The service window helps checking the balanced state of the differential protection This window displays the status of all disconnect switches in all bays shows the measured current values and the calculated delta and sum current values in all three phases If the protection is switched over to TEST state there is possibility to check the consistency o
38. pendent disconnecor switches e g sectionalisers in order to receive the optical fiber cable pairs P and R Cover plate 8 empty place or other two additional COM3 boards if more feeders are connected to the bus bar S s T Cover plate 8TE empty place or other two additional COM3 boards if more feeders are connected to the bus bar U s V Cover plate 8 empty place or other two additional COMG boards if more feeders are connected to the bus bar The structure of the OGYD2 EP numerical bus bar and breaker failure protection and the number of the applied COM3 communication units depends on the primary configuration of the substation 5 5 The front plate of the central unit and the large graphic display Fig 16 shows the front plate of the central unit The right side of the front plate contains the man machine interface of all EuroProt devices The detailed description is in the EuroProt complex protection hardware and software description and user s manual The LED assignment is described in chapter 3 7 The left side of the front plate is the location of the large graphic display To the right of this display the six push buttons with left arrow serve the communication with the display When the device is energized the graphic display shows the bus bar configuration with the bays of the substation This scheme shows the status of the disconnectors and the status signal errors are indicated as well C
39. rip current is Id Izm I The biasing current is with similar procedure K Is K zm 1 n a where n is the number of the bays a is the subtracted load current value In the following explanation a 0 setting value is supposed The trip equation is Id K Is which yields with substitution of the expressions above Izm I 1 K This equation helps when setting the K biasing factor supposing the maximal Izm or determination of the maximal zm in case of a given K setting Example if the current transformer with rated current of 250 A primary saturates at 1722500 A and the setting is K 0 5 then Izm 3 T 30 In 7500 A if the setting is 0 8 then Izm 9 IT 90 n 22500 These data show that for stationary state this protection provides a sufficient protection If a current transformer is at the saturation limit in stationary state the fault current is equal with the saturation value then the flux reaches the saturation level and the time to saturation of the current transformer is 10 ms and the current peak value is Ir 1 42 Ir If the current exceeds this value then the current transformer saturates in ompiled by Approved by Date Page p y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 13 50 PROTEC A OGYD2 EP User s manual Electronics Co Ltd shorter time than 10 ms based on the principle of equalty of areas the time to saturation can
40. romagnetic radiofrequency interference test IEC 801 3 Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 46 50 PROTEC lectronics Co Ltd OGYD2 EP User s manual 6 2 Setting ranges Parameters of the measuring element primary values Basic sensitivity I base setting 50 5000 A steps 10 A Biasing slope K 50 80 steps 5 Maximum value of feeder load I Offset a 0 5000 A steps 10 A CT circuit monitoring failure current Iset CT error 10 5000 A steps 25 A Parameters of the bays stored in the central unit 1 feeder CT primary rated current CTPr A 50 5000 A steps 25 A 2 feeder CT primary rated current CTPr A 50 5000 A steps 25 A feeder CT primary rated current CTPr A 50 5000 A steps 25 A Timer parameters CT circuit monitoring timer operating and drop out delay 100 32000 ms CT error delay steps 10 ms CB failure protection 1 timer BF timer 1 0 32000 ms steps 10 ms CB failure protection 2 timer BF timer 2 0 32000 ms steps 10 ms Disconnect switch disagreement protection timer Disc status error timer 1 60 s steps 1s Voltage relay parameters Feeder voltage checks Bay voltage condition 0 7 Un fixed value Communication parameters
41. ronics Co Ltd In case of external fault even if the time to saturation is below 2 ms there can be a considerable time span when Id gt K Is see Fig 5 If this time is more than 8 ms then the measuring element generates a false trip command for external fault This can occur in case of high grade of transient saturation h 20 11 243 ae LS Is Id s Fig 5 External fault with 1 ms time to med saturation Is ld Id K Is Is ld Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 16 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd To avoid false trip command in case of external fault the OGYD2 EP device uses the following method As it can be seen in Fig 5 at the beginning the biasing current is always above the trip current and in this time the measuring element blocks the trip command This blocking can never occur in case of internal fault so in case of initial blocking it can be always supposed that the fault is an external fault So if the biasing current is above the tripping current even in one step then the measuring element switches over from 8 to 25 for the count limit of tripping conditions the duration is in this case 25 ms This method assures correct operation in case of extreme saturation as well The application of the method above does not result increasing operating time in case of interna
42. s extended by a driver unit for fiber optic link OXO In this configuration this bay module exploits the power supply unit the integrated input units and the A D converter of the EuroProt device To receive the status signals of the by disconnectors the free digital inputs of the device can be applied or an additional optically isolated binary input module can be inserted in the distance protection or overcurrent protection If the bus configuration to be protected contains bus disconnectors as well the status signals from these devices are to be connected to the central unit All bay units are interconnected with the central unit with a high sped serial line in the form of a pair of fiber optic cable send and receive This fiber optic connection is applied in the central configuration as well The parameter settings of the protection system is stored in the central unit s CPU MAIN module the parameter setting process and the communication with the system is controlled by this unit too The further tasks of this unit are event recording controlling the auxiliary modules supervising the signals of the optically isolated input module of the central unit operating the output relays and running the PROTLOG equation system After energizing the unit and after each parameter modifications the CPU main sends the parameters of the configuration to the CPU OGYD located in the central unit as well After receipt of these data the bus bar differ
43. s 15 lt MIL te 16 ay I R AS 4 o so TRIP 115 HELLE K L TRI I T H J 19 20 SELF TEST x KL 21 BF START x gd 22 ON X m jous K 23 oFF x kt _ 24 ON aus p KI H 25 OFF 4 29 CLOCK SYNCH C H 31 32 POWER SUPPLY 33 34 CB OFF Fig 9 Connections serving the OGYD2 EP functions of a bay unit of DTI OGYD2 EP type Compiled by Approved by Date Page Ferenc Radv nszki and Gyula P ka L szl Eperjesi 14 09 2004 31 50 PROTECTA Electronics Co Ltd OGYD2 EP User s manual U y CT2 2 INPUT OPTO 290 e 1 2 BUS eron 3 BUS rom 4 BF START E 6 fos is Ps TRIPLET es s orro rs fo yn R4E 1 iu C De TRIP LR e ame se R4I Denomination num N Denomination 1 E TRIP ILS MIL RIPILT 0 K8 SELF TEST EBEECEE ti N K8 SELF TEST Fig 10 Complete list of connections of a DTI OGYD2 EP device Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 32 50 PROTEC A lectronics Co Ltd OGYDJ2 EP User
44. tifiers positions and connectors o Denomination ET l ED R4E EI K14 6 Ki4 Miz 8 K15 UNI 19 5 sssi SN 5 Ede _ N t 2 C BUS BAR DISC 57 Ks 6 8 9 sz 2 POWER SUPPLYP 17 Fig 14 Complete list of connections of an OGYD2 EP central device Compiled by Approved by Date Page Ferenc Radv nszki and Gyula P ka L szl Eperjesi 14 09 2004 36 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd 000000 000000 OOOOOO COM3 20 20 mo wl Fig 15 rear view of an OGYD2 EP central device example ompiled by Approved by Date Page p y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 37 50 PROTEC lectronics Co Ltd OGYD2 EP User s manual Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 38 50 PROTEC OGYD2 EP User s manual lectronics Co Ltd 5 4 Modules of the central unit The remaining part of this chapter describes the modules of the central unit as an example for the possi
45. uring element automatically generates trip command The command detected on the output relay is somewhat delayed because of the operating time of the relay The duration of the trip impulse is at least 500 ms the algorithm resets the command only after this time delay if the conditions are reset meantime The drop off ratio of the trip current is 1 The bus bar differential protection function can be disabled by an output variable BB prot disable of the PROTLOG equations Using the parameter BB diff prot disable the function can be fix disabled In this case the assigned LED is signaling the disabled state and the PROTLOG equation has no influence The measuring principle in case of external fault is shown in Fig 3 ompiled by Approved by Date Page y pp y Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 11 50 PROTECTA Electronics Co Ltd OGYD2 EP User s manual 11 12 13 Fig 3 Measurement of external fault The top of Fig 3 shows a simple bus bar section configuration where Bay 4 has an external fault The currents in the healthy bays flow in the same direction the fault current in Bay 4 is the sum of these currents and flows in inverse direction Because of concentrated fault current the CT in Bay 4 can be saturated The second row of Fig 3 shows that opposite to the sum of the healthy bay current I1 I2 I3 the I4 bay current is not exactly the inverse
46. uring element is reconfigured In normal operation when receiving faulty status signals from the disconnectors the device keeps the previous state and generates error signals but supposing the previous bus bar configurations keeps on operating If the status error is detected after energizing or following parameter changes the protection remains disabled until the faulty status is corrected and generates Differential protection disabled and Breaker failure disabled status signals as well The central unit sends synchronous signals to each bay units via fiber optic connection and the bay units answer with sending sampled current values in each phases to the central unit These values are used by the assigned measuring elements of the central unit The measuring elements of the central unit perform the following tasks summation of the sampled I momentary current values for the bays connected to the bus section I eo 23 1 then the current DC component is filtered by subtracting the actual value from that sampled 10 ms before and the difference is divided by two 1 E I 10 d pl 2 the same procedure is repeated with the subsequent sampled value and with the value sampled by 10 ms before that and the procedure is repeated ten times These ten calculated values are averaged receiving the d trip current 10 VEM Id __ 10 additionally to the procedure above from the absolute value of the sampled J mo
47. x PROTEC lectronics Co Ltd OGYD2 EP Bus bar differential protection and circuit breaker failure protection based on optical fiber cable links User s Guide Budapest 2004 Nr EO 13 13935 01 PROTEC A OGYD2 EP User s manual lectronics Co Ltd CONTENTS L Heldofappheati n a aina e a a a N R 3 2 Mam characteristics ciu pest dca i teet DER tO NO C dub E aayqa a 4 3 Working principle aeta Y 6 3 1 Numerical bus bar differential 6 31 1 Voltage CONDON so poen en hc ae ee ee ie ie ais ne as 18 3 1 2 Supervising the current transformer 18 341 9 Tuberoptic cable empresa s ie ieu CUR QE Se 19 3 2 Digital breaker failure protection p detiene 19 4 Information from and to OGYD2 EP bus bar differential and breaker failure protection21 4 1 Parameter setting and setting ranges 21 4 2 lastof evaluated events used ber 22 43 MASE Gl GI STEAL events aa a nu ven dave DEN redu Den Mt secu ione es 22 AA ISU of ECD messages mass opes unan uQ epu aio cM tenet Mat cu d 23 4 5 On line InfOrImation eiecti oci erede eerta d pe ees a RA eA tenes 23 4 6 Inputs and outputs of the PROTLOG equations
48. ying the internal fault all currents flow in the same direction The time function in the second row of Fig 2 drawn dashed in the first half period has half value because of the average calculation o ie Tasso ic based on th led val tion I Y I and that sampled cm is based on the sampled value summation 1 gt and that sample 10 ms before Compiled by Approved by Date Page Ferenc Radvanszki and Gyula P ka L szl Eperjesi 14 09 2004 10 50 PROTEC A OGYD2 EP User s manual lectronics Co Ltd The Isp time function in the third row of Fig 2 drawn dashed in the first half period has L I s p 5 10 half value too because of the average calculation based on the calculation mentioned before 7 5 hz a if a gt 0 and because in normal operation these values are continuously zero as the a load current value is continuously subtracted The bottom curve in Fig 2 shows Id and K Is which is the result of averaging 10 values 10 10 b 2 bo Id and K Is K _ 10 10 As before fault both d and K Is are zero the bottom curves in Fig 2 increase step by step In the evaluation there is no intentional time delay or measured value exclusion Tripping is generated after 8 consecutive starting of the function In case of internal fault as Fig 2 shows Id is continuously above K s and after 8 comparisons the meas
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