EMI and EMC Aspects of a Brushless Repulsion Motor/Drive

1. Presented by DynaMotors, Inc. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive 2004 SMMA

2. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive Background • Inverters that drive induction motors, brushless dc motors and switched reluctance motors can produce EMI and cause EMC problems. 2004 SMMA

3. Typical PWM Motor Drive Inverter 2004 SMMA

4. EMI and EMC Aspects of a Brushless Repulsion Motor/drive Background • Inverters that drive induction motors, brushless dc motors and switched reluctance motors can produce EMI and cause EMC problems. • Cabling between drive inverters and motors can conduct common-mode energy to the motor stator windings which might cause damaging bearing currents. 2004 SMMA

5. Hi-Frequency Common-Mode current paths 2004 SMMA

6. EMI and EMC Aspects of a Brushless Repulsion Motor/drive Background • Inverters that drive induction motors, brushless dc motors and switched reluctance motors can produce EMI and cause EMC problems. • Cabling between drive inverters and motors can conduct common-mode energy the motor stator windings which might cause damaging bearing currents. • Long cables between the drive inverter and the motor may set up standing voltage waves that reduce the motor insulation life. 2004 SMMA

7. EMI and EMC Aspects of a Brushless Repulsion Motor/drive Background • Inverters that drive induction motors, brushless dc motors and switched reluctance motors can produce EMI and cause EMC problems. • Cabling between drive inverters and motors can conduct common-mode energy the motor stator windings which might cause damaging bearing currents. • Long cables between the drive inverter and the motor may set up standing voltage waves that reduce the motor insulation life. • Filters added to drive inverters designed to reduce or eliminate the above problems must carry the motor rated current. 2004 SMMA

8. Typical filter add-ons used with drive inverters 2004 SMMA

9. EMI and EMC Aspects of a Brushless Repulsion Motor/drive Background • Inverters that drive induction motors, brushless dc motors and switched reluctance motors can produce EMI and cause EMC problems. • Cabling between drive inverters and motors can conduct common-mode energy the motor stator windings which might cause damaging bearing currents. • Long cables between the drive inverter and the motor may set up standing voltage waves that reduce the motor insulation life. • Filters added to drive inverters to reduce the above problems must carry the motor rated current. • Shielded cables are often needed to reduce EMI. 2004 SMMA

10. Solutions to the EMI and EMC problem Ways to minimize the EMI and EMC problem • Use only linear (sine-wave) drives for adjustable-speed motors 2004 SMMA

11. Solutions to the EMI and EMC problem Ways to minimize the EMI and EMC problem • Use only linear (sine-wave) drives for adjustable-speed motors • Add shielded cabling 2004 SMMA

12. Solutions to the EMI and EMC problem Ways to minimize the EMI and EMC problem • Use only linear (sine-wave) drives for adjustable-speed • Add shielded cabling • Use very high-frequency carrier PWM drives (100-200kHz) with filtered outputs and perfectly shielded and grounded enclosures 2004 SMMA

13. Solutions to the EMI and EMC problem Ways to minimize the EMI and EMC problem • Use only linear (sine-wave) drives for adjustable-speed • Add shielded cabling • Use very high-frequency carrier PWM drives (100-200kHz) with filtered outputs and perfectly shielded and grounded enclosures • Build the drive into the motor – still needs output and input filters to limit bearing currents but does help reduce EMI caused by drive to motor cables. 2004 SMMA

14. Solutions to the EMI and EMC problem Ways to minimize the EMI and EMC problem • Use only linear (sine-wave) drives for adjustable-speed • Add shielded cabling • Use very high-frequency carrier PWM drives (100-200kHz) with filtered outputs and perfectly shielded and grounded enclosures • Build the drive into the motor – still needs output and input filters to limit bearing currents but does help reduce EMI caused by drive to motor cables. • Use a brushless repulsion motor. 2004 SMMA

15. 48 Frame 4-pole 1/2HP HVAC Brushless Repulsion Motor with Integrated Drive Control 2004 SMMA

16. Construction of a Brushless Repulsion Motor 2004 SMMA

17. Armature coil is open Armature coil is shorted Simplified image of a Brushless Repulsion Motor 2004 SMMA

18. Flux pattern in 4-pole Brushless Repulsion Motor 2004 SMMA

19. Coil Switch side of 48 Frame HVAC Motor PC Board(Mounted on armature shaft) 2004 SMMA

20. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive Radiated and Conducted Noise Measurements on the 48 frame HVAC Motor • Radiated standards were FCC Class A 3m and CE standard EN55022 Class A 3m • Both the horizontal and vertical planes were measured in the tests • Conducted noise standard was EN55022 Class A 2004 SMMA

21. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive 2004 SMMA

22. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive 2004 SMMA

23. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive 2004 SMMA

24. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive 2004 SMMA

25. EMI and EMC Aspects of a Brushless Repulsion Motor 2004 SMMA

26. EMI and EMC Aspects of a Brushless Repulsion Motor Conclusions • The adjustable speed brushless repulsion motor eliminates the need for high frequency PWM drive inverters that produce radiated and conducted energy and high frequency common-mode currents that might damage bearings. 2004 SMMA

27. EMI and EMC Aspects of a Brushless Repulsion Motor Conclusions • The adjustable speed brushless repulsion motor eliminates the need for high frequency PWM drive inverters that produce radiated and conducted energy and high frequency common-mode currents that might damage bearings. • The problem of common-mode currents is eliminated because all the switching is done in a closed space on the armature. 2004 SMMA

28. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive Conclusions • The adjustable speed brushless repulsion motor eliminates the need for high frequency PWM drive inverters that produce radiated and conducted energy and high frequency common-mode currents that might damage bearings. • The problem of common-mode currents is eliminated because all the switching is done in a closed space on the armature. • The filtering requirement for the input power line is eliminated. 2004 SMMA

29. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive Conclusions • The adjustable speed brushless repulsion motor eliminates the need for high frequency PWM drive inverters that produce radiated and conducted energy and high frequency common-mode currents that might damage bearings. • The problem of common-mode currents is eliminated because all the switching is done in a closed space on the armature. • The filtering requirement for the input power line is reduced. • No filtering is needed for the space between the controller and the armature. 2004 SMMA

30. EMI and EMC Aspects of a Brushless Repulsion Motor/Drive Thankyou Your Questions Please Presented by DynaMotors, Inc. 2004 SMMA