Title: EMI and EMC Aspects of a Brushless Repulsion Motor/Drive
1EMI and EMC Aspects of a Brushless Repulsion
Motor/Drive
- Presented by DynaMotors, Inc.
2EMI 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.
3Typical PWM Motor Drive Inverter
4EMI 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.
5Hi-Frequency Common-Mode current paths
6EMI 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.
7EMI 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.
8Typical filter add-ons used with drive inverters
9EMI 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.
10Solutions to the EMI and EMC problem
- Ways to minimize the EMI and EMC problem
- Use only linear (sine-wave) drives for
adjustable-speed motors
11Solutions 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
12Solutions 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
13Solutions 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.
14Solutions 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.
1548 Frame 4-pole 1/2HP HVAC Brushless Repulsion
Motor with Integrated Drive Control
16Construction of a Brushless Repulsion Motor
17Simplified image of a Brushless Repulsion Motor
18Flux pattern in 4-pole Brushless Repulsion Motor
19Coil Switch side of 48 Frame HVAC Motor PC Board
(Mounted on armature shaft)
20EMI 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
21EMI and EMC Aspects of a Brushless Repulsion
Motor/Drive
22EMI and EMC Aspects of a Brushless Repulsion
Motor/Drive
23EMI and EMC Aspects of a Brushless Repulsion
Motor/Drive
24EMI and EMC Aspects of a Brushless Repulsion
Motor/Drive
25EMI and EMC Aspects of a Brushless Repulsion Motor
26EMI 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.
27EMI 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.
28EMI 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.
29EMI 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.
30EMI and EMC Aspects of a Brushless Repulsion
Motor/Drive
- Thankyou
- Your Questions Please
- Presented by DynaMotors, Inc.