1. 1 Variable Frequency AC Source Students: Kevin Lemke Matthew Pasternak Advisor: Steven D. Gutschlag 1

2. 2 Outline Project overview High level block diagram Subsystems Lab work Equipment Future work 2

3. 3 Project Goals Variable Frequency AC Source (VFACS) Capable of delivering 208 [Vrms] and 5 [A] Sine wave frequency range from 0 to 60 [Hz] 3

4. 4 Project Significance VFACS used to vary shaft speed in a three phase induction motors Constant Volts/Hertz ratio to provide variable torque & speed operation without exceeding motor current ratings Variable Frequency Drive (VFD) Replaces control flow control valves in pump systems Replaces gear box speed control Improve operating power factor 4 [1]

5. 5 High Level System Block Diagram 5

6. 6 PWM Generation Controller Produces dual sided PWM signals for the Gate Drive Circuitry Use a LabVIEW based controller and cDAQ module from National Instruments When completed, ability to control both single phase and three phase systems 6

7. 7 Single-Phase PWM Generation Controller 7

8. 8 Produce TTL level PWM signals Produce waveforms representative of sine waves from 0-60 [Hz] Combination of Upper and Lower PWM signals Produced from Upper and Lower Triangle Waves Produce waveforms following appropriate V/Hz based on DC rail voltage 8

9. 9 Single-Phase PWM Generation Controller 9 Simulink based PWM Generation Controller V/Hz control Ideal LC Filter testing

10. 10 Gate Drive Circuitry High speed signal isolator and driver Use optical isolators and gate driver chips to isolate and amplify gate drive signals to the Inverter Optical isolators and gate drivers chosen for speed and robustness 10

11. 11 Initial Gate Drive Circuitry 11

12. 12 Gate Drive Circuitry Capable of switching at 1% duty cycle and 15 [kHz] switching frequency Optical Isolator 6N137 Optocoupler Isolate cDAQ outputs from Inverter, Filter, and Load Voltages Gate Driver IR2110 Amplify PWM from TTL level to V ge =15 [V] 12

13. 13 Redesigned Gate Drive Circuitry Changes Replaced IR2110/6n137 with HCPL3120 Robustness Real-estate Simplicity Verified that this chip would provide the same switching speed as the IR2110 [2] 13

14. 14 Inverter PWM Signal Amplifier for AC machine application Use IGBT pairs and DC rails to amplify PWM signal IGBTs used for high voltage capability, low on-state voltage, and availability Single- and three-phase configurations 14

15. 15 Single-Phase Inverter 15

16. 16 Three-Phase Inverter 16

17. 17 Inverter Configurations Single-phase Inverter Fairchild FMG2G75US60 IGBT Pair Each IGBT will receive one PWM signal Output one dual-sided PWM signal representing the necessary sine wave Have 0 and 100 [VDC] rails capable of providing 15 [A] for testing Three-phase Inverter Three single-phase inverters Single-phase inputs 120 ⁰ out of phase from any other input pair Capable of 5 [A] per phase IRF520N MOSFETS for testing 17

18. 18 Filter LC filter Used to extract sine wave encoded in PWM signal Three identical filters used (one for each phase) Components rated for 400 [V] and 15 [A] Practical filter in LRC configuration 18 LRC Filter Design Equations

19. 19 Filter Updates 19 Practical LRC Filter Frequency Response LR Motor Filter Frequency Response

20. 20 Filter Updates Analysis of three phase induction motor filtering capabilities LRC meter to measure L & R of the motor to be used for testing Comparison filtering characteristics of motor and proposed LC filter Determined that inherent LR filter in the motor can replace the Filter subsystem 20

21. 21 Load Overall system output used for testing Initially resistive-inductive (RL) for both single and three-phase systems Final tests will be performed on a three-phase induction motor Shall be able to draw the rated power from the system 21

22. 22 Opto-coupler Simulation 6N137 Opto-coupler Simulation] PSPICE Circuit Exported to Excel for plotting

23. 23 Opto-coupler Simulation Inverted output Minimal rise time 15 [kHz] test input signal

24. 24 Gate Driver Testing Gate Driver and Opto-coupler construction HCPL3120 Gate Driver construction HCPL3120 Gate Driver testing with IFR520N MOSFET single phase inverter DC rails 0 and 18 [VDC] +DC rail/2 5 [V] 24 Single-Phase Inverter Test with IRF520N MOSFET Ch1 Load Voltage Ch2 Load Current

25. 25 LabVIEW Data Type Testing Basic cDAQ Interface Analog Input Digital Output (TTL) Basic PWM Generation Controller in LabVIEW for data type testing Point by Point vs Waveform data types 25

26. 26 Basic Controller & Data Type Simulation 26 Simulation of basic, single-phase PWM generation controller 1 [Hz] sine wave 10 [Hz] triangle wave 1 [kHz] sampling frequency Single-Phase PWM Generation Controller Simulation

27. 27 Controller Design 27 Based on Simulink model Uses waveform data type Configured for three phase operation Built and output digital waveform from sine & triangle wave comparison

28. 28 Sine and Triangle Wave Generation Generate sine and triangle waves User specified signal and sampling frequency Extract amplitude value for comparison

29. 29 PWM Signal Generation Comparison of upper and lower triangle waves to sine wave for A- phase Digital waveform generation Used sampling information from sine and triangle wave generation Digital waveform sent to output stage B & C phase comparison uses 120° and 240° phase shift respectively

30. 30 Output Stage Using DAQmx Toolkit Digital waveform input to while loop Create and write to physical channel on cDAQ B & C phase output stages follow this design

31. 31 Controller Simulation 31 Simulation of basic, three-phase PWM generation controller 1 [Hz] sine wave 15 [kHz] triangle wave 150 [kHz] sampling frequency Three-Phase PWM Generation Controller Simulation

32. 32 Low Frequency Output Testing 32 PWM Generation Controller Test 1 [Hz] Sine wave 10 [Hz] Triangle Wave 1 [kHz] sampling frequency Single-Phase Simulation Single-Phase Low Frequency Simulation

33. 33 Low Frequency Output Testing Oscilloscope graph of low frequency output test Output matches digital waveform from LabVIEW scope Single-Phase Low Frequency Output Test

34. 34 High Frequency Output Testing 34 PWM Generation Controller Test 60 [Hz] sine wave and 15 [kHz] triangle wave LabVIEW scope reading exported to excel

35. 35 High Frequency Output Testing 35 Output from cDAQ as seen by oscilloscope 60 [Hz] sine wave 15 [kHz] triangle wave Waveforms from LabVIEW scope and oscilloscope match Single-Phase Upper Half PWM Signal High Frequency Output Test

36. 36 Equipment & Parts List LabVIEW Student Edition NI-cDAQ-9174 Data Acquisition Chassis NI-9401 Digital I/O NI-9221 Analog Input Module NI-9211 Thermal Couple IR2110/2113 6N137 Opto-coupler HCPL3120 Gate Driver IRF520 MOSFET FMG2G75US60 IGBT Pair with anti-parallel diodes 7MBP75RA060-09 Inverter module Sources and Scopes available in Power Lab 36

37. 37 Future Work 37 Current Year PWM Generation Controller Volts/Hertz ratio Simultaneous upper and lower PWM outputs Load voltage feedback input Future Years Single phase inverter with FMG2G75US60 IGBT pairs 7MBP75RA060-09 Inverter module Three phase implementation

38. 38 Questions? 38 References [1] http://www.globalindustrial.com/p/motors/ac-motors-definite-purpose/explosion-proof- motors/baldor-motor-idxm7170t-10-hp-2700-rpm?infoParam.campaignId=T9F&gclid=CJa- kMDzhb4CFexcMgodOBsAWA&gclsrc=aw.ds [2] www.avagotech.com/docs/AV02-0161EN

39. 39 Switching Speed Calculation FMG2G75US60 minimum switching speed Switching speed = Gate Charge [nC]/ Gate Current [A] Switching speed = 200 [nC]/ 2 [A] * 4 = 0.4 [μs] using maximum current for IR2110 and HCPL-3120 39 Plot of Gate Charge Characteristics for FMG2G75US60

40. 40 Datasheets http://www.fairchildsemi.com/ds/6N/6N137.pdf http://www.daedalus.ei.tum.de/attachments/article/257/IR2110_IR2 110S_IR2113_IR2113S.pdf http://www.daedalus.ei.tum.de/attachments/article/257/IR2110_IR2 110S_IR2113_IR2113S.pdf http://pdf.datasheetcatalog.com/datasheet/fairchild/FMG2G75US60. pdf http://pdf.datasheetcatalog.com/datasheet/fairchild/FMG2G75US60. pdf http://www.datasheetcatalog.com/datasheets_pdf/H/C/P/L/HCPL- 3120.shtml http://www.datasheetcatalog.com/datasheets_pdf/H/C/P/L/HCPL- 3120.shtml https://www.futurlec.com/Transistors/IRF520.shtml 40

41. 41 Flow Chart 41

42. 42 RLC Filter Design Equations 42

43. 43 RLC Filter Response 43

44. 44 Pictures 44

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