System, apparatuses, methods, and computer program products for
Contents
1. means for storing a previously measured temperature value the previously measured temperature value being obtained at a time of taking a previous measurement of the winding resistance of the electric motor means for automatically correcting the data representative of the temperature of the windings based on the previ ously measured temperature value means for determining a corrected winding resistance value ofthe electric motor windings the corrected wind ing resistance value being determined based on the cor rected temperature data means for storing the determined corrected winding resis tance value of the electric motor windings means for electronically displaying on a resistance versus time graph the determined corrected winding resistance value of the electric motor windings and means for determining when to refurbish or replace the electric motor based on data from the resistance versus time graph 11 The system of claim 10 wherein said means for storing the first input data said means for storing the second input data said means for storing a previously measured tempera US 8 427 192 B2 15 ture value and said means for storing the determined cor rected winding resistance value are part of a computer read able and programmable non volatile memory device 12 The system of claim 10 wherein the data from the resistance versus time graph includes one or more previously determined corrected winding resist2. a technician or user inputs the data from the readings into the respective fields in the user interface Furthermore as will be discussed with reference to apparatus 200 in FIG 2 the functionality of at least elements 140 and 150 and optionally element 160 can be part of one apparatus or device 200 Though FIG 1 shows only measuring or input elements 140 150 and 160 processor 110 can receive other inputs In various embodiments data inputs shown in the exemplary user interface of FIGS 4 through 10 may be further inputted For example the following information may be added name plate data year installed or last rehabbed miscellaneous notes on each motor data of measurement measured insula tion resistance value measured temperature etc In various embodiments some of the data may be manually entered such as year of motor installation and date of measurement and some data may be received electronically such as mea sured insulation resistance value measured temperature and or measured humidity Any suitable combination of inputs may be provided Thus in various embodiments resistance value readings may be manually entered via a user interface whereas in other embodiments resistance value readings can be electronically received and input The inputs are not lim ited to those shown in the exemplary user interface of FIGS 4 through 10 and any suitable inputs or data may be input for motor testing and analysis Pro
3. means by which a user manually inputs to said receiving portion data for at least one of the electric motor resistance measurement and the motor temperature measurement In various embodiments the apparatus can further comprise an electric motor resistance measuring portion to measure a resistance of the electric motor and a motor temperature measuring portion to mea sure a temperature of the electric motor Optionally a portion of the display may be a touch screen and said receiving portion may receive inputs via the touch screen In various embodiments the processor may determine when to refur bish or replace the electric motor based on a slope of decline ofthe most recent two normalized resistance values Alterna tively in various embodiments the processor may determine when to refurbish or replace the electric motor based on a comparison of the most recently determined normalized resistance value with a predetermined resistance value and the processor may determine that the electric motor should be refurbished or replaced when the most recently determined resistance value is at or below the predetermined resistance value In various embodiments optionally the processor may be further operative to predict at least one of electric motor failure and a point in time at which the electric motor will not operate satisfactorily BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate embodiments ofthe disclosed subject ma
4. or replace the electric motor based on data from the US 8 427 192 B2 3 resistance versus time graph can make the determination of when to refurbish or replace the electric motor based on a slope of decline of the most recent two determined corrected winding resistance values over time Optionally or alterna tively said means for determining when to refurbish or replace the electric motor based on data from the resistance versus time graph can make the determination of when to refurbish or replace the electric motor based on a comparison of the determined corrected winding resistance value with a predetermined winding resistance value and said means for determining when to refurbish or replace the electric motor can determine that the motor should be refurbished or replaced when the determined corrected winding resistance value is at or below a predetermined winding resistance value In various embodiments when the determined corrected winding resistance value is at or below the predetermined winding resistance value said means for determining when to refurbish or replace the electric motor determines that the electric motor should be refurbished or replaced immediately Optionally or alternatively when the determined corrected winding resistance value is at or below a predetermined wind ing resistance value said means for determining when to refurbish or replace the electric motor determines that the electric motor has failed In vario
5. various embodiments processing element 110 may calculate and out put on display element 130 a new time interval for retesting i e for the next test the winding resistance of the electric motor For example the processing element may decrease the time for a next winding resistance measurement based on the determined slope and or whether the most recently deter mined corrected winding resistance value is at or below the predetermined winding resistance value Storage element 120 can be any suitable storage element such as a database in the form of a non volatile memory device such as EEPROM or RAM Though FIG 1 shows storage element 120 being outside processing element 110 in various embodiments it can be located internal to processing element 110 Furthermore though shown as a single unit in FIG 1 storage element 120 may be a plurality of individual storage units such as different locations in one storage unit or multiple individual storage devices wherein each unit or device stores information for one particular electric motor or one characteristic of each of the electric motors Thus storage element 120 can storage a variety of information and data for a particular motor as well as a variety of information for a number of particular motors For example data shown in the user interface of FIGS 4 through 10 may be stored in storage element 120 such as normalized winding resistance data Data stored in storage element 120 f
6. 0 may be able to perform all of the functions of the individual elements 110 120 130 140 150 and 160 of system 100 For example apparatus 200 may be a hand held portable electronic apparatus a techni cian can use for periodic electric motor testing and analysis Motor resistance portion 240 can either measure motor resis tance essentially a built in spot or single Megohm Megaohm device or receive data representative of a measured motor winding resistance value such as by way of a wireless or wired signal from a spot or single Megohm Megaohm device or by way of a user manual input via a user interface Simi larly motor temperature portion 250 and humidity portion 260 can either measure motor temperature and humidity respectively or receive data representative of a measured motor temperature and humidity Item 210 is a processor item 220 is a storage element and item 230 is a display element These items are substantially the same as described above for system 100 and will not be described again Not explicitly shown apparatus 200 also may have a user inter face suchas a touchscreen or keypad or combination thereof FIG 3 is a flow chart of a method 300 according to various embodiments of the disclosed subject matter The method 300 and variations thereof may be readily implemented in a com puter program product comprised of a computer readable storage medium having stored thereon software instructions that when executed by a p
7. IG 10B is a screen shot of the third tab shown in FIG 6 populated with data according to various embodiments of the disclosed subject matter FIG 10C is a screen shot of the fourth tab shown in FIG 7 showing a resistance versus time curve plotted on a chart and based on the data shown in the tabs of FIGS 10A and 10B according to various embodiments of the disclosed sub ject matter DETAILED DESCRIPTION In general various embodiments of the disclosed subject matter include determining and storing normalized electric motor winding resistance values over an extended period of time in order to identify a characteristic or soon to be char acteristic of the electric motor such as remaining lifetime of the motor predicted or estimated time to motor failure or unsatisfactory operation thereof and or motor failure Such information may be used as an indicator for replacing or refurbishing the electric motor or as an indicator for perform ing preventative maintenance on the electric motor Inciden tally the disclosed subject matter can be implemented for any suitable electric motor such as synchronous machines induc tion machines and de machines The normalized electric motor winding resistance values may be taken once per rela tively long periods of time such as every month every quar ter every season or every year Embodiments of the disclosed subject matter do not contemplate determining winding resis tance values incl
8. a2 United States Patent Barbour II US008427192B2 US 8 427 192 B2 Apr 23 2013 10 Patent No 45 Date of Patent 54 SYSTEM APPARATUSES METHODS AND COMPUTER PROGRAM PRODUCTS FOR ELECTRIC MOTOR TESTING AND ANALYSIS 76 Inventor David M Barbour II Ona WV US Notice Subject to any disclaimer the term of this patent is extended or adjusted under 35 U S C 154 b by 376 days 21 Appl No 12 805 309 22 Filed Jul 23 2010 65 Prior Publication Data US 2012 0019281 A1 Jan 26 2012 51 Int CI G01R 31 34 2006 01 52 U S CI 324 765 01 58 Field of Classification Search 324 762 01 762 1 324 765 01 702 58 64 65 318 727 490 318 802 823 See application file for complete search history 56 References Cited U S PATENT DOCUMENTS 6 128 583 A 10 2000 Dowling 7 127 373 B2 10 2006 House et al 7 659 687 B2 2 2010 Wahler et al 318 806 7 769 552 B2 8 2010 Colby etal 702 65 2004 0263342 Al 12 2004 Matlock et al OTHER PUBLICATIONS NEMA Standards Publication Condensed MG 1 2002 Information Guide for General Purpose Industrial AC Small and Medium Squir RECEIVING ELECTRIC MOTOR DATA rel Cage Induction Motor Standards National Electrical Manufac turers Association 2002 IEEE Std 43 2000 R2006 IEEE Recommended Practice for Test ing Insulation Resistance of Rotating Machinery Oct 12 2000 Insulation S
9. ance values the previ ously determined corrected insulation resistance values hav ing been previously stored by said means for storing the determined corrected winding resistance value 13 The system of claim 10 wherein said means for deter mining when to refurbish or replace the electric motor based on data from the resistance versus time graph makes the determination of when to refurbish or replace the electric motor based on a slope of decline of the most recent two determined corrected winding resistance values over time 14 The system of claim 10 wherein said means for determining when to refurbish or replace the electric motor based on data from the resis tance versus time graph makes the determination of when to refurbish or replace the electric motor based on acomparison of the determined corrected winding resis tance value with a predetermined winding resistance value and wherein said means for determining when to refurbish or replace the electric motor determines that the motor should be refurbished or replaced when the determined corrected winding resistance value is at or below a pre determined winding resistance value 15 The system of claim 14 wherein when the determined corrected winding resistance value is at or below the prede termined winding resistance value said means for determin ing when to refurbish or replace the electric motor determines that the electric motor should be refurbished or replaced imme
10. appara tuses methods and computer program products for electric motor testing and analysis SUMMARY Various embodiments of the disclosed subject matter 1 one some or all can include a method e g a computerized method of modifying the frequency of testing an electric motor The method can comprise receiving as a first input data representative of insulation resistance of windings of the electric motor receiving as a second input data representa tive of a temperature associated with the windings during a measuring of the insulation resistance of the electric motor windings automatically and electronically normalizing the data representative of the temperature associated with the windings based on a common temperature wherein the com mon temperature is forty degrees Celsius determining a nor malized insulation resistance value of the electric motor windings by applying the normalized temperature data to the data of the first input which is representative of the insulation resistance of the windings automatically storing in a non volatile storage medium the normalized insulation resistance value of the electric motor windings electronically plotting and displaying the determined normalized insulation resis tance value on a resistance versus time graph the graph including a previously determined normalized insulation resistance value wherein the previously determined normal ized insulation resistance value has been pr
11. cessing element 110 can be for example a computer such as laptop or a desktop a hand held device such as a personal digital assistant PDA or cell phone a micropro cessor a microcontroller a computerized processor etc Pro cessing element 110 can receive inputs such as those dis cussed above For example processing element 110 may receive data representing a temperature measurement of the electric motor and automatically correct or normalize the data to a common temperature such as forty degrees Celsius or a previously other normalized temperature value based on a previously measured and recorded temperature e g the tem perature of the motor the last time it was tested Processing element 110 also may receive data representing a winding resistance measurement and determine a normalized winding resistance value based on the normalized temperature value and the received winding resistance measurement data so that so that winding resistance value trending over time can be tracked and analyzed at a constant relative temperature Optionally in various embodiments processing element 110 also may receive data representing a humidity or moisture associated with the electric motor such as a humidity or moisture content in the vicinity or general local area or space ofthe electric motor Optionally in various embodiments the processing element 110 may correct or normalize the received humidity or moisture data to a common humidit
12. ct normalized data can be stored in a storage medium Unless this is the first time a motor has been tested the storage medium should have stored therein previous select normalized data Select normalized data to be stored in a storage medium can include the determined normalized insulation resistance value s Optionally normalized tem perature values can also be stored In various embodiments data may have been previously or later stored such as the information shown in the exemplary user interface shown in FIGS 4 through 10 In various embodiments the storing can be done automatically S308 can include comparing the determined normalized winding resistance In various embodiments the determining normalized winding resistance can be compared with one or more previously determining normalized winding resistance values For example the normalized winding resistance values current and previous can be plotted and displayed in a resistance versus time graph comparison between the cur rent normalized winding resistance value and one or more previous values can be made to determine a slope e g declining slope for the normalized winding resistance val ues In various embodiments the slope determination can be done electronically based on data for the graph or of the graph The determined slope can be compared with one or more predetermined values For example if the slope of decline exceeds a predetermined slope value the time peri
13. ctronic device and the second data is input electronically via a second electronic device Various embodiments ofthe disclosed sub ject matter can optionally comprise making the next determi nation of a normalized insulation resistance value of the elec tric motor automatically storing in the nonvolatile storage medium said next determination of normalized insulation resistance value ofthe electric motor windings electronically plotting and displaying said determined next normalized insulation resistance value on the resistance versus time graph and electronically determining a slope of decline ofthe insulation resistance of the windings over time based on said determined next normalized insulation resistance value Various embodiments of the disclosed subject matter also can include a system for testing an electric motor The system can comprise means for measuring a winding resistance of the electric motor means for measuring a temperature of the windings of the electric motor means for receiving as a first input data representing the measured winding resistance means for receiving as a second input data representing the measured temperature of the windings means for storing the first input data means for storing the second input data means for storing a previously measured temperature value the previously measured temperature value being obtained at a time of taking a previous measurement of the winding resistance of the electric moto
14. diately 16 The system of claim 14 wherein when the determined corrected winding resistance value is at or below a predeter mined winding resistance value said means for determining when to refurbish or replace the electric motor determines that the electric motor has failed 17 The system of claim 10 further comprising means for measuring a humidity associated with the elec tric motor means for receiving as a third input data representing the measured humidity means for storing the third input data and 20 25 30 35 16 means for automatically correcting the data representative of the humidity wherein the corrected winding resistance value is deter mined based on the corrected humidity data 18 The system of claim 10 wherein said means for deter mining when to refurbish or replace the electric motor pre dicts at least one of electric motor failure and a point in time at which the electric motor will not operate satisfactorily 19 A computer program product comprised of a non transitory computer readable storage medium having stored thereon software instructions that when executed by a pro cessor cause the processor to perform operations comprising receiving data representative of an insulation winding resistance measurement of an electric motor under test receiving data representative of a temperature measure ment of the windings taken at or around the time of the insulation winding resistance
15. e humidity to a predetermined humidity wherein said determining a normalized insulation resistance value ofthe electric motor windings can further use the normalized humidity Various embodiments of the disclosed subject matter can further include a hand held portable electronic apparatus for periodic electric motor testing and analysis The apparatus can comprise a receiving portion to receive inputs associated with an electric motor resistance measurement and a motor temperature measurement a processor to calculate a normal ized temperature value based on the received motor tempera ture measurement input and to determine a normalized resis tance value based on the normalized temperature value and the received electric motor resistance measurement a memory storage unit to store a plurality of said normalized resistance values determined based on electric motor testing performed at different times and a display to display electric motor testing and analysis information In various embodi ments the processor can be operative to produce data for output on the display in graph format wherein the display may show a plot ofthe plurality of said normalized resistance values versus time and wherein based on the plotted plural ity of said normalized resistance values versus time the pro cessor can automatically determine when to refurbish or replace the electric motor Optionally said receiving portion may bea user interface that provides a
16. ecting time of failure of the electric motor based on the slope of decline 3 The method of claim 1 further comprising comparing the slope of decline with a second predeter mined slope value stored in the nonvolatile storage medium and refurbishing or replacing the existing motor if the slope of decline exceeds the second predetermined slope value 4 The method of claim 1 further comprising performing the next determination of a normalized insulation resistance value of the electric motor based on said decreased time interval wherein the time interval between a time of said previously determined normalized insulation resistance value and a time of said determined normalized insulation resis 5 10 20 25 30 35 40 45 50 55 60 65 14 tance value is one year and the decreased time interval is from six months to one month in one month increments 5 The method of claim 1 further comprising receiving as a third input data representative of a humidity in the vicinity ofthe electric motor during the measuring of the insulation resistance of the electric motor wind ings and automatically and electronically normalizing the data rep resentative of the humidity wherein said determining the normalized insulation resis tance value of the electric motor windings further includes applying the normalized humidity data 6 The method of claim 1 further comprising performing Single or Spot Mego
17. ed humidity data associated with the motor may be used to determine the normalized winding resistance values Turning now to the figures FIG 1 is a block diagram of a system 100 according to various embodiments of the dis closed subject matter System 100 can be comprised ofa processing element 110 a storage element 120 a display element 130 a resistance measuring element 140 and a temperature measuring ele ment 150 Not explicitly shown in FIG 1 processing element 110 also may include on board storage or memory such as memory for processing and storing computer programs for execution Optionally system 100 may include a humidity or moisture measuring element 160 An electric motor under test 1 for taking a resistance measurement and other measure ments is not shown in FIG 1 In various embodiments the motor under test will be disconnected from its normal power supply and discharged Generally system 100 can operate to take read or receive aresistance measurement of one or more electric motor wind ings either stator or rotor windings such as insulation wind ing resistance In various embodiments resistance measuring element 140 can be used to take measure or receive the resistance ofthe electric motor windings Resistance measur ing element 140 can be any suitable resistance measuring system apparatus or device For example in various embodi ments resistance measuring element 140 is a single or spot megohm
18. efurbishing or replacing the existing motor if the slope of decline exceeds the second predetermined slope value Various embodiments of the disclosed subject matter can also optionally comprise performing the next determination of a normalized insulation resistance value of the electric motor based on the decreased time wherein the time interval between a time of said previ 20 25 30 35 40 45 50 55 60 65 2 ously determined normalized insulation resistance value and a time of said determined normalized insulation resistance value is one year and the decreased time interval is from six months to one month in one month increments Optionally in various embodiments the method can comprise receiving as a third input data representative of a humidity in the vicinity of the electric motor during the measuring of the insulation resistance of the electric motor windings and automatically and electronically normalizing the data representative of the humidity wherein said determining the normalized insula tion resistance value of the electric motor windings further includes applying the normalized humidity data Optionally the method can further comprise performing a Single or Spot Megohm Megaohm Reading method to measure the insula tion resistance of the windings of the electric motor Option ally the first and second data are input electronically Option ally the first data is input electronically via a first ele
19. er to the exact construction and operation illustrated and described and accordingly all suit able modifications and equivalents may be resorted to falling within the scope of the disclosed subject matter It should be appreciated that any steps described above may be repeated in whole or in part in order to perform a contemplated electric motor testing and or analysis task Fur ther it should be appreciated that the steps mentioned above may be performed on a single or distributed processor Also the processes elements components modules and units described in the various figures of the embodiments above may be distributed across multiple computers or systems or may be co located in a single processor or system Embodiments of the method system apparatus and com puter program product 1 software for electric motor test ing and analysis may be implemented on a general purpose computer a special purpose computer a programmed micro processor or microcontroller and peripheral integrated circuit element an ASIC or other integrated circuit a digital signal processor a hardwired electronic or logic circuit such as a discrete element circuit a programmed logic device such as a PLD PLA FPGA PAL or the like In general any process capable of implementing the functions or steps described herein can be used to implement embodiments ofthe method system or computer program product for providing or pre senting data Further
20. eviously stored in the nonvolatile storage medium electronically determining a slope of decline of the insulation resistance of the windings over time by comparing the previously determined normal ized insulation resistance value with the determined normal ized insulation resistance value and comparing the slope of decline with a first predetermined slope value stored in the nonvolatile storage medium The method can further com prise decreasing a time interval until the next determination of a normalized insulation resistance value of the electric motor as compared to a time interval between a time of said previ ously determined normalized insulation resistance value and a time of said determined normalized insulation resistance value if the slope of decline exceeds the first predetermined slope value keeping same the time interval until the next determination of a normalized insulation resistance value of the electric motor if the slope of decline does not exceed the first predetermined slope value and electronically outputting a time for the next determination of normalized insulation resistance Optionally the method can further comprise pro jecting time of failure of the electric motor based on the slope of decline Optionally in various embodiments of the disclosed sub ject matter the method can further comprise comparing the slope of decline with a second predetermined slope value stored in the nonvolatile storage medium and r
21. f the disclosed subject matter is not limited to this example however and the humidity may be normalized based on an algorithm executed by processing element 110 Though FIG 1 shows an arrow connecting humidity measuring element 160 with processing element 110 these two elements are not necessarily physically connected e g by an electrical wir ing For example in various embodiments humidity mea suring element 160 can be a separate temperature measuring element from the processing element and data or information from the humidity measuring element 160 can be entered manually by a user of the processing element for example Alternatively or optionally data or information from the humidity measuring element 160 can be transmitted wire lessly from the humidity measuring element 160 to the pro cessing element 110 Though elements 140 150 and 160 are shown in FIG 1 as being three separate elements in various embodiments one input interface can be provided to receive data representative of resistance and temperature and optionally humidity For example the input interface can be a user interface such as a graphical user interface or touch screen capable of receiving user input So the aforementioned elements in this case would be three different input fields of the interface Measurements 20 25 30 35 40 45 50 55 60 65 8 using other respective devices thus have been used to obtain these readings and
22. hm Megaohm Reading method to mea sure the insulation resistance of the windings of the electric motor 7 The method of claim 1 wherein the first and second data are input electronically 8 The method of claim 1 wherein the first data is input electronically via a first electronic device and the second data is input electronically via a second electronic device 9 The method of claim 1 further comprising making the next determination of a normalized insulation resistance value of the electric motor automatically storing in the nonvolatile storage medium said next determination of normalized insulation resis tance value of the electric motor windings electronically plotting and displaying said determined next normalized insulation resistance value on the resistance versus time graph and electronically determining a slope of decline of the insula tion resistance of the windings over time based on said determined next normalized insulation resistance value 10 A system for testing an electric motor the system comprising means for measuring a winding resistance of the electric motor means for measuring a temperature of the windings of the electric motor means for receiving as a first input data representing the measured winding resistance means for receiving as a second input data representing the measured temperature of the windings means for storing the first input data means for storing the second input data
23. is operative to take read or receive a temperature measurement Temperature measuring element 150 can be any suitable element for taking a tem perature ambient or otherwise of an electric motor under test such as a thermometer an infrared thermometer etc Though FIG 1 shows an arrow connecting temperature mea suring element 150 with processing element 110 these two elements are not necessarily physically connected by an electrical wiring For example in various embodiments temperature measuring element 150 can be a separate tem perature measuring element from the processing element and data or information from the temperature measuring element 150 can be entered manually by a user of the processing element for example Alternatively or optionally data or information from the temperature measuring element 150 can be transmitted wirelessly from the temperature measuring element 150 to the processing element 110 Optionally in various embodiments system 100 also can operate to take read or receive a humidity or moisture mea surement associated with electric motor Humidity measuring element 160 can take read or receive a humidity measure ment One example of a humidity measuring element 160 would be where the electric motor under test is in an air conditioned room and a user or technician enters zero or a very low humidity value into a user interface The humidity measuring element 160 according to various embodiments o
24. lly the process will not repeat until one month a quarter six months or one year after the most recent pass through the flow chart FIGS 4 through 10 an exemplary user interface with vari ous data fields The data fields may be populated by any suitable means such as automatically and electronically by a processing element by a user s manual input or a combina tion thereof FIGS 10A through 10C shown an example of output results based on data input to the system The data fields are in now way limited to those shown in this example user interface Having now described embodiments of the disclosed sub ject matter it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting having 20 25 30 35 40 45 50 55 60 65 12 been presented by way of example only Numerous modifi cations and other embodiments e g combinations rear rangements etc are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the disclosed subject matter and any equivalent thereto It can be appreciated that variations to the present disclosed subject matter would be readily apparent to those skilled in the art and the present disclosed subject matter is intended to include those alternatives Further since numerous modifications will readily occur to those skilled in the it is not desired to limit the disclosed subject matt
25. measurement automatically normalizing the temperature to a common temperature determining a normalized insulation resistance value of the electric motor windings using the normalized tempera ture automatically storing the normalized insulation resistance value plotting and displaying the determined normalized insula tion resistance value on a graph the graph including at least one previously determined normalized insulation resistance value and estimating based on one or more data points correspond ing to the normalized insulation resistance values plot ted on the graph an amount of operational time of the electric motor until failure or unsatisfactory operation thereof 20 The computer program product of claim 19 wherein the processor can further perform the following operations receiving data representative of a humidity measurement taken in the general area of the electric motor under test at or around the time of the insulation winding resistance measurement and automatically normalizing the humidity to a predeter mined humidity wherein said determining a normalized insulation resistance value of the electric motor wind ings further uses the normalized humidity
26. megaohm reading or measurement system appara tus or device such as a megaohm meter Though FIG 1 shows an arrow connecting resistance measuring element 140 with processing element 110 these two elements are not necessarily physically connected e g by electrical wiring For example in various embodiments resistance measuring element 140 can be a separate resistance measuring element US 8 427 192 B2 7 from the processing element and data or information from the resistance measuring element 140 can be entered manually by a user of the processing element for example Alternatively or optionally data or information from the resistance mea suring element 140 can be transmitted wirelessly from the resistance measuring element 140 to the processing element 110 System 100 also can operate to take read or receive a temperature measurement associated with electric motor The temperature measurement can be taken at any suitable loca tion and by any suitable means For example if the electric motor has been at rest for a predetermined period of time it may be assumed that the windings at are at ambient tempera ture of the interior or exterior of the windings or motor Thus in various embodiments the temperature measurement is an ambient temperature measurement of the electric motor and may be representative of the temperature of one or more of the electric motor windings In various embodiments tempera ture measuring element 150
27. more embodiments of the disclosed method sys tem apparatus and computer program product for electric motor testing and analysis may be readily implemented fully or partially in software using for example object or object oriented software development environments that provide portable source code that can be used on a variety of computer platforms Alternatively embodiments of the disclosed method system and computer program product for electric motor testing and analysis can be implemented partially or fully in hardware using for example standard logic circuits or a VLSI design Other hardware or software can be used to implement embodiments depending on the speed and or effi ciency requirements of the systems the particular function and or a particular software or hardware system micropro cessor or microcomputer system being utilized Embodi ments of the method system apparatus and computer pro gram product for electric motor testing and analysis can be implemented in hardware and or software using any known or later developed systems or structures devices and or soft ware by those of ordinary skill in the applicable art from the functional description provided herein and with a general basic knowledge of the computer arts Incidentally the following documents are hereby incorpo rated by reference in their entireties U S Pat No 7 127 373 IEEE Standard 43 2000 R2006 IEEE Recommended Prac tice for Testing Insula
28. ntative maintenance on the electric motor 20 Claims 12 Drawing Sheets 302 NORMALIZING SELECT MOTOR DATA STORING SELECT NORMALIZED DATA COMPARING NORMALIZED WINDING RESISTANCE OUTPUTTING INFORMATION BASED ON COMPARISION RESULT 304 306 308 310 312 U S Patent Apr 23 2013 Sheet 1 of 12 US 8 427 192 B2 100 V 130 120 110 160 140 150 FIG 1 U S Patent Apr 23 2013 Sheet 2 of 12 US 8 427 192 B2 200 230 220 210 FIG 2 U S Patent Apr 23 2013 Sheet 3 of 12 US 8 427 192 B2 300 301 J START COMPARING NORMALIZED WINDING S308 RESISTANCE OUTPUTTING INFORMATION BASED ON 310 COMPARISION RESULT FIG 3 U S Patent Apr 23 2013 Sheet 4 of 12 US 8 427 192 B2 vr t ichan SH an apprime vean ivo mont or vaar tanofeciured T RER Mosriaiactumr Ctog i SSS SSS UU Se ERATUM AUN ea e Aat U S Patent Apr 23 2013 Sheet 5 of 12 US 8 427 192 B2 Test Data ci motor from ver database sad en by elect Mor ID wi aan click M m i i Jedi of reesuremant ance in ihm d ew f i m i i The corrected insulation resistance value Inr this test at 4 degrees Cis U S Patent Apr 23 2013 Sheet 6 of 12 US 8 427 192 B2 r
29. od for a next resistance test may be shortened whereas if the slope of decline does not exceed the predetermined slope value the time period for the next resistance test may be kept the same as a previous time period Optionally if the slope of decline exceeds another predetermined value it can indicate that the motor has failed or needs refurbishing or replacing Optionally or alternatively the presently determining wind ing resistance value may be compared to a predetermined value Based on the comparison result a characteristic or pre dicted or estimated characteristic of the electric motor such as remaining lifetime of the motor predicted or estimated time to motor failure or unsatisfactory operation thereof and or motor failure can be identified or determined For example based on the data of or for the graph an amount of operational time of the electric motor until failure or unsatis factory operation thereof may be estimated At S310 information is outputted based on the results of the comparison For example an electronic display may display a time for the next determination of normalized insulation resistance such as remaining lifetime of the motor predicted or estimated time to motor failure or unsatisfactory operation thereof and or motor failure At 5312 the method can end or if further long term periodic testing is to occur the method 300 may return to 301 and repeat the process As indicated earlier genera
30. ogi E 2 amp PME E amp S p amp Ro E ix U S Patent Apr 23 2013 Sheet 7 of 12 US 8 427 192 B2 Choose amp motor and press the button to s rest FIG 7 U S Patent Apr 23 2013 Sheet 8 of 12 US 8 427 192 B2 an delete a Set t molor data sa in hackug WAWA FIG 8 U S Patent Apr 23 2013 Sheet 9 of 12 US 8 427 192 B2 ick the Stun feds fo add iniemeation on the intormeton far each motor here f t Ost tab to enter teat deta for each motor ian degradation curve for each motor ick tie tab to viene params ofthe mo Sick the Egt tab to delete a rotor oc get of data f 9 U S Patent Apr 23 2013 Sheet 10 of 12 Enter the year insti ty hast maul imeem ers are unciam Nu Serial Fia 10A US 8 427 192 B2 WM vu hay day U S Patent Apr 23 2013 Sheet 11 of 12 US 8 427 192 B2 fron your ciate 3e buttniosswe the data Han aces i i i i i i i i i i H HESS iw hevi uud FiG 10B U S Patent Apr 23 2013 Sheet 12 of 12 US 8 427 192 B2 prn nre prre us es E c E ae Date of Test FIG 10C US 8 427 192 B2 1 SYSTEM APPARATUSES METHODS AND COMPUTER PROGRAM PRODUCTS FOR ELECTRIC MOTOR TESTING AND ANALYSIS FIELD The disclosed subject matter relates to systems
31. or any electric motor having been previously tested and data recorded with system 100 may be retrieved so that this information can be displayed by display element 130 and or used by processing element 110 for further calculations based on new measurements Display element 130 can be any suitable electronic display such as a computer monitor a touchscreen LED or LCD display on a hand held device etc Display element 130 can display electric motor testing and analysis information such 5 40 45 55 65 10 as the information shown in the user interface of FIGS 4 through 10 In various embodiments display element 130 can have a graphing capability or functionality whereby it can output a resistance versus time curve based on historical and current normalized electric motor winding resistance read ings Processing element 110 can interpret resistance and time data for or of the graphical display to determine a con dition of the motor windings Data also may be entered by display element 130 for example if the display element has touchscreen capabilities Furthermore not explicitly shown in FIG 1 a manual user interface may be provided to enter data such as a computer keyboard a mouse a keypad etc FIG 2 shows an apparatus 200 according to various embodiments of the disclosed subject matter Apparatus 200 is similar to system 100 in functionality That is to say in various embodiments apparatus 20
32. ormalized temperature automatically storing the normalized insulation resistance value plotting and display ing the determined normalized insulation resistance value on a graph the graph including at least one previously deter mined normalized insulation resistance value and estimat ing based on one or more data points corresponding to the normalized insulation resistance values plotted on the graph an amount of operational time of the electric motor until failure or a time of unsatisfactory operation thereof Alterna tively instead of plotting and graphing the normalized insu lation resistance values in various embodiments the proces sor can perform the following operations comparing the determined normalized insulation resistance value with one or more previously determined normalized insulation resis tance values and estimating based on a change between the determined normalized insulation resistance value and one or more of the previously determined insulation resistance val ues an amount of operational time of the electric motor until 20 25 30 35 40 45 50 55 60 65 4 failure or unsatisfactory operation thereof Optionally the processor can further perform the operations of receiving data representative of a humidity measurement taken in the gen eral area of the electric motor under test at or around the time of the insulation winding resistance measurement and auto matically normalizing th
33. r means for automatically cor recting the data representative of the temperature of the wind ings based on the previously measured temperature value means for determining a corrected winding resistance value of the electric motor windings the corrected winding resis tance value being determined based on the corrected tempera ture data means for storing the determined corrected winding resistance value of the electric motor windings means for electronically displaying on a resistance versus time graph the determined corrected winding resistance value of the elec tric motor windings and means for determining when to refurbish or replace the electric motor based on data from the resistance versus time graph Optionally in various embodi ments said means for storing the first input data said means for storing the second input data said means for storing a previously measured temperature value and said means for storing the determined corrected winding resistance value can be part of a computer readable and programmable non volatile memory device In various embodiments optionally the data from the resistance versus time graph may include one or more previously determined corrected winding resis tance values wherein the previously determined corrected insulation resistance values was previously stored by said means for storing the determined corrected winding resis tance value Optionally said means for determining when to refurbish
34. rocessor cause the processor to perform operations as described herein and as appreciated to those skilled in the computer arts Method 300 can start at S301 and proceed to 302 At S302 electric motor data can be received for a motor under test or to be tested In various embodiments received data can include data representative of insulation resistance of windings of the electric motor and data representative of a temperature associated with the windings In various embodi ments the temperature is taken at or around a time as that of a measurement of insulation resistance of windings of the motor Optionally received data can include data representa tive of a humidity associated with the electric motor at the time of taking the measurement of insulation resistance of windings of the motor Received data also can include a time e g the date of taking the measurement of insulation resis tance of windings of the motor Received data also can include data shown in the user interface of FIGS 4 through 10 304 can include normalizing the temperature data to a common temperature and normalizing or correcting the data representative of the measured insulation resistance value based on the normalized temperature Optionally if a humid ity data is received this data also may be normalized to a common humidity In various embodiments the normaliza tion can be done automatically and electronically US 8 427 192 B2 11 At S306 sele
35. tion Resistance of Rotating Machinery ASTM D257 2009 Standard Test Methods for DC Resis tance for Conductance of Insulating Materials EASA 2001 How to Get the Most From Your Electric Motors FLUKE 2007 Insulation Resistance Testing Application Note MEG GER 2006 A Stitch in Time CEORDR 110 2 42 1992 US 8 427 192 B2 13 Motor Windings at Navigations and Lake Facilities and Insu lation System Testing Presented by Don Shaw Company PdMA Corporation Product Development Department The invention claimed is 1 A computerized method of modifying the frequency of testing an electric motor comprising receiving as a first input data representative of insulation resistance of windings of the electric motor receiving as a second input data representative of a tem perature associated with the windings during a measur ing of the insulation resistance of the electric motor windings automatically and electronically normalizing the data rep resentative of the temperature associated with the wind ings based on a common temperature the common tem perature being forty degrees Celsius determining a normalized insulation resistance value of the electric motor windings by applying the normalized temperature data to the data of the first input which is representative of the insulation resistance of the wind ings automatically storing in a nonvolatile storage medium the normalized insulation resistance value of the elec
36. tric motor windings electronically plotting and displaying the determined nor malized insulation resistance value on a resistance ver sus time graph the graph including a previously deter mined normalized insulation resistance value the previously determined normalized insulation resistance value having been previously stored in the nonvolatile storage medium electronically determining a slope of decline of the insula tion resistance of the windings over time by comparing the previously determined normalized insulation resis tance value with the determined normalized insulation resistance value comparing the slope of decline with a first predetermined slope value stored in the nonvolatile storage medium if the slope of decline exceeds the first predetermined slope value decreasing a time interval until the next determi nation of a normalized insulation resistance value of the electric motor as compared to a time interval between a time of said previously determined normalized insula tion resistance value and a time of said determined nor malized insulation resistance value if the slope of decline does not exceed the first predeter mined slope value keeping same the time interval until the next determination of a normalized insulation resis tance value of the electric motor and electronically outputting a time for the next determination of normalized insulation resistance 2 The method of claim 1 further comprising proj
37. tter The disclosed subject matter will be best understood by reading the ensuing specification in con junction with the drawing figures in which like elements are designated by like reference numerals and wherein FIG 1 is a block diagram of a system according to various embodiments of the disclosed subject matter FIG 2 is a block diagram of an apparatus according to various embodiments of the disclosed subject matter US 8 427 192 B2 5 FIG 3 shows a flow chart of a method according to various embodiments of the disclosed subject matter FIG 4 is a screen shot of a first tab of a user interface according to various embodiments of the disclosed subject matter FIG 5 is a screen shot of a second tab of a user interface according to various embodiments of the disclosed subject matter FIG 6 is a screen shot of a third tab of a user interface according to various embodiments of the disclosed subject matter FIG 7 is a screen shot of a fourth tab of a user interface according to various embodiments of the disclosed subject matter FIG 8 is a screen shot of a fifth tab of a user interface according to various embodiments of the disclosed subject matter FIG 9 is a screen shot of a sixth tab of a user interface according to various embodiments of the disclosed subject matter FIG 10A is a screen shot of the second tab shown in FIG 5 populated with data according to various embodiments of the disclosed subject matter F
38. uding normalized values at shorter time intervals such as every second minute hour day or week The time period between determining normalized winding resistance values may change based on analysis of determin ing winding resistance values Such determination at to changing time period for determining normalized resistance values may be electronically calculated and the results of the calculation displayed Furthermore embodiments of the dis closed subject matter store or record the normalized electric motor winding resistance values in correlation to the date in which the values were determined Various embodiments of the disclosed subject matter can include measuring electric motor winding resistance and motor temperature In various embodiments these two mea surements are performed at or about the same time Based on the resistance measurement or measurements as well as the 20 25 30 35 40 45 50 55 60 65 6 temperature measurement a normalized resistance value for the windings is calculated The calculation can be done auto matically upon input of the aforementioned resistance and temperature values The winding resistance measurement can be normalized to a common temperature and electronically displayed in a resistance e g in MOhms MQ versus time e g t in months quarters seasons years or combination thereof graph including one or more previously normalized winding resistance values from pre
39. us embodiments the system can further comprise means for measuring a humidity asso ciated with the electric motor means for receiving as a third input data representing the measured humidity means for storing the third input data and means for automatically correcting the data representative ofthe humidity wherein the corrected winding resistance value cab be determined based on the corrected humidity data Optionally said means for determining when to refurbish or replace the electric motor can predict at least one of electric motor failure or a point in timeat which the electric motor will not operate satisfactorily In various embodiments the system can further comprise means for adjusting the frequency of further winding resis tance testing Various embodiments of the disclosed subject matter also can include a computer program product comprised of a computer readable storage medium having stored thereon software instructions that when executed by a processor cause the processor to perform operations comprising receiving data representative of an insulation winding resis tance measurement of an electric motor under test receiving data representative of a temperature measurement of the windings taken at or around the time of the insulation winding resistance measurement automatically normalizing the tem perature to a common temperature determining a normalized insulation resistance value of the electric motor windings using the n
40. vious winding resistance and temperature measurements The determined normalized or corrected winding resistance value also can be stored and or compared to a predetermined value in order to diagnose a characteristic of the electric motor The temperature can be normalized to a predetermined temperature such as a tem perature of a previously taken temperature measurement associated with the one or more windings Insulation resis tance varies inversely on an exponential basis with winding temperature Thus for the testing contemplated by the dis closed subject matter temperature normalization is important to obtain reliable determinations at to normalized motor winding resistance In various embodiments at least the previous winding resistance measurements were previously stored ina memory unit for example Based on information for or from the graph a characteristic or predicted or estimated characteristic of the electric motor such as remaining lifetime of the motor pre dicted or estimated time to motor failure or unsatisfactory operation thereof and or motor failure can be identified As alluded to above a frequency of further electric motor testing and analysis may be modified or kept the same based infor mation from or for the graph For example the frequency may be increased 1 the time until the next test may be decreased as compared to the time between the two previous tests Optionally in various embodiments normaliz
41. which the electric motor will not operate satisfactorily Optionally in various embodiments processing element 110 can determine a slope of the most recently determined winding resistance value and at least the second most recently determined wind ing resistance value Based on the determined slope the pro cessing element 110 may determine that the motor has failed will soon fail including estimating a date of predicted fail ure or is operating unsatisfactorily Thus processor 110 may cause an indication by way of display element 130 that the electric motor has failed will fail is operating unsatisfacto rily an estimated date of motor failure or that the electric motor needs to be refurbished or replaced Optionally or alternatively in various embodiments processing element 110 can make a comparison of the determined corrected winding resistance value with a predetermined winding resis tance value For example if the determined corrected wind ing resistance value is at or below the predetermined winding resistance value processor 110 may determine that the motor has failed will soon fail including estimating a date of pre dicted failure or is operating unsatisfactorily Thus proces sor 110 may cause an indication by way of display element 130 that the electric motor has failed will fail is operating unsatisfactorily an estimated date of motor failure or that the electric motor needs to be refurbished or replaced In
42. y or moisture value Thus optionally the normalized humidity or moisture data may be used to determine the corrected or normalized winding resistance value Processing element 110 can cause some or all of the nor malized data to be stored either in on board or off board memory Storage of such data may be used for comparison with future testing results For example processing element 110 may send to storage element 120 normalized wiring resistance data values In various embodiments the storage normalized winding resistance values are from sequential individual tests ofthe winding resistance ofthe electric motor over an extended period of time Processing element 110 also may send to display element 130 normalized wiring resis tance data for output thereon In various embodiments the normalized wiring resistance data may be plotted on a graph US 8 427 192 B2 9 of normalized wiring resistance versus time In various embodiments the most recently determined normalized wir ing resistance value may be plotted with previously deter mined normalized wiring resistance values retrieved from storage element 120 In various embodiments the processing element 110 can automatically determine when to refurbish or replace the electric motor based data for or from the plot of normalized resistance values versus time Alternatively or optionally the processing element 110 can predict at least one of electric motor failure and a point in time at
43. ystem Testing presented by Don Shaw Product Devel opment Department PAMA Corporation A Stitch in Time The Complete Guide to Electrical Testing Megger 2006 ASTM D257 07 Standard Test Methods for DC Resistance or Con ductance of Insulating Materials ASTM International May 15 2007 CEORDR 1110 2 42 Motor Windings at Navigational and Lake Facilities Department of the Army U S Army Engineer Division Ohio River Corps of Engineers Sep 11 1992 How to Get the Most From Your Electric Motors Electrical Apparatus Service Association 2001 Insulation Resistance Testing Application Note Fluke Corporation 2007 cited by examiner Primary Examiner Tung X Nguyen 57 ABSTRACT Systems apparatuses methods and computer program prod ucts i e software for electric motor testing and analysis Electric motor winding resistance and motor temperature are measured The resistance measurement is normalized to a common temperature and electronically displayed in a resis tance versus time graph including one or more previously normalized resistance values from previous resistance and temperature measurements Based on information from the graph a prediction or estimation can be made as to the remaining acceptable or satisfactory operating time of the electric motor Such prediction or estimation may be used as an indicator for replacing or refurbishing the electric motor oras an indicator for performing preve
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