2004 SMMA2004 SMMA 11

EMI and EMC Aspects of a EMI and EMC Aspects of a Brushless Repulsion Brushless Repulsion

Motor/DriveMotor/Drive

Presented by DynaMotors, Inc.Presented by DynaMotors, Inc.

2004 SMMA2004 SMMA 22

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/DriveMotor/Drive

BackgroundBackground• Inverters that drive induction motors, brushless dc Inverters that drive induction motors, brushless dc

motors and switched reluctance motors can produce EMI motors and switched reluctance motors can produce EMI and cause EMC problems. and cause EMC problems.

2004 SMMA2004 SMMA 33

Typical PWM Motor Drive InverterTypical PWM Motor Drive Inverter

2004 SMMA2004 SMMA 44

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/driveMotor/drive

BackgroundBackground• Inverters that drive induction motors, brushless dc motors Inverters that drive induction motors, brushless dc motors

and switched reluctance motors can produce EMI and and switched reluctance motors can produce EMI and cause EMC problems.cause EMC problems.

• Cabling between drive inverters and motors can conduct Cabling between drive inverters and motors can conduct common-mode energy to the motor stator windings which common-mode energy to the motor stator windings which might cause damaging bearing currents.might cause damaging bearing currents.

2004 SMMA2004 SMMA 55

Hi-Frequency Common-Mode current paths Hi-Frequency Common-Mode current paths

2004 SMMA2004 SMMA 66

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/driveMotor/drive

BackgroundBackground• Inverters that drive induction motors, brushless dc motors Inverters that drive induction motors, brushless dc motors

and switched reluctance motors can produce EMI and and switched reluctance motors can produce EMI and cause EMC problems.cause EMC problems.

• Cabling between drive inverters and motors can conduct Cabling between drive inverters and motors can conduct common-mode energy the motor stator windings which common-mode energy the motor stator windings which might cause damaging bearing currents.might cause damaging bearing currents.

• Long cables between the drive inverter and the motor may Long cables between the drive inverter and the motor may set up standing voltage waves that reduce the motor set up standing voltage waves that reduce the motor insulation life.insulation life.

2004 SMMA2004 SMMA 77

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/driveMotor/drive

BackgroundBackground• Inverters that drive induction motors, brushless dc motors Inverters that drive induction motors, brushless dc motors

and switched reluctance motors can produce EMI and and switched reluctance motors can produce EMI and cause EMC problems.cause EMC problems.

• Cabling between drive inverters and motors can conduct Cabling between drive inverters and motors can conduct common-mode energy the motor stator windings which common-mode energy the motor stator windings which might cause damaging bearing currents.might cause damaging bearing currents.

• Long cables between the drive inverter and the motor may Long cables between the drive inverter and the motor may set up standing voltage waves that reduce the motor set up standing voltage waves that reduce the motor insulation life.insulation life.

• Filters added to drive inverters designed to reduce or Filters added to drive inverters designed to reduce or eliminate the above problems must carry the motor rated eliminate the above problems must carry the motor rated current.current.

2004 SMMA2004 SMMA 88

Typical filter add-ons used with drive invertersTypical filter add-ons used with drive inverters

2004 SMMA2004 SMMA 99

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/driveMotor/drive

BackgroundBackground• Inverters that drive induction motors, brushless dc motors Inverters that drive induction motors, brushless dc motors

and switched reluctance motors can produce EMI and and switched reluctance motors can produce EMI and cause EMC problems.cause EMC problems.

• Cabling between drive inverters and motors can conduct Cabling between drive inverters and motors can conduct common-mode energy the motor stator windings which common-mode energy the motor stator windings which might cause damaging bearing currents.might cause damaging bearing currents.

• Long cables between the drive inverter and the motor may Long cables between the drive inverter and the motor may set up standing voltage waves that reduce the motor set up standing voltage waves that reduce the motor insulation life.insulation life.

• Filters added to drive inverters to reduce the above Filters added to drive inverters to reduce the above problems must carry the motor rated current.problems must carry the motor rated current.

• Shielded cables are often needed to reduce EMI.Shielded cables are often needed to reduce EMI.

2004 SMMA2004 SMMA 1010

Solutions to the EMI and EMC problemSolutions to the EMI and EMC problem

Ways to minimize the EMI and EMC problemWays to minimize the EMI and EMC problem

• Use only linear (sine-wave) drives for adjustable-speed Use only linear (sine-wave) drives for adjustable-speed motorsmotors

2004 SMMA2004 SMMA 1111

Solutions to the EMI and EMC problemSolutions to the EMI and EMC problemWays to minimize the EMI and EMC problemWays to minimize the EMI and EMC problem

• Use only linear (sine-wave) drives for adjustable-speed Use only linear (sine-wave) drives for adjustable-speed motorsmotors

• Add shielded cablingAdd shielded cabling

2004 SMMA2004 SMMA 1212

Solutions to the EMI and EMC problemSolutions to the EMI and EMC problem

Ways to minimize the EMI and EMC problemWays to minimize the EMI and EMC problem

• Use only linear (sine-wave) drives for adjustable-speedUse only linear (sine-wave) drives for adjustable-speed• Add shielded cablingAdd shielded cabling• Use very high-frequency carrier PWM drives (100-Use very high-frequency carrier PWM drives (100-

200kHz) with filtered outputs and perfectly shielded and 200kHz) with filtered outputs and perfectly shielded and grounded enclosuresgrounded enclosures

2004 SMMA2004 SMMA 1313

Solutions to the EMI and EMC problemSolutions to the EMI and EMC problem

Ways to minimize the EMI and EMC problemWays to minimize the EMI and EMC problem

• Use only linear (sine-wave) drives for adjustable-speedUse only linear (sine-wave) drives for adjustable-speed• Add shielded cablingAdd shielded cabling• Use very high-frequency carrier PWM drives (100-Use very high-frequency carrier PWM drives (100-

200kHz) with filtered outputs and perfectly shielded and 200kHz) with filtered outputs and perfectly shielded and grounded enclosuresgrounded enclosures

• Build the drive into the motor – still needs output and input Build the drive into the motor – still needs output and input filters to limit bearing currents but does help reduce EMI filters to limit bearing currents but does help reduce EMI caused by drive to motor cables.caused by drive to motor cables.

2004 SMMA2004 SMMA 1414

Solutions to the EMI and EMC problemSolutions to the EMI and EMC problemWays to minimize the EMI and EMC problemWays to minimize the EMI and EMC problem

• Use only linear (sine-wave) drives for adjustable-speedUse only linear (sine-wave) drives for adjustable-speed• Add shielded cablingAdd shielded cabling• Use very high-frequency carrier PWM drives (100-Use very high-frequency carrier PWM drives (100-

200kHz) with filtered outputs and perfectly shielded and 200kHz) with filtered outputs and perfectly shielded and grounded enclosuresgrounded enclosures

• Build the drive into the motor – still needs output and input Build the drive into the motor – still needs output and input filters to limit bearing currents but does help reduce EMI filters to limit bearing currents but does help reduce EMI caused by drive to motor cables.caused by drive to motor cables.

• Use a brushless repulsion motor.Use a brushless repulsion motor.

2004 SMMA2004 SMMA 1515

48 Frame 4-pole 1/2HP HVAC Brushless Repulsion 48 Frame 4-pole 1/2HP HVAC Brushless Repulsion Motor with Integrated Drive ControlMotor with Integrated Drive Control

2004 SMMA2004 SMMA 1616

Construction of a Brushless Repulsion MotorConstruction of a Brushless Repulsion Motor

2004 SMMA2004 SMMA 1717

Simplified image of a Brushless Repulsion Simplified image of a Brushless Repulsion MotorMotor

Armature coil is Armature coil is openopen

Armature coil is Armature coil is shortedshorted

2004 SMMA2004 SMMA 1818

Flux pattern in 4-pole Brushless Repulsion MotorFlux pattern in 4-pole Brushless Repulsion Motor

2004 SMMA2004 SMMA 1919

Coil Switch side of 48 Frame HVAC Motor PC BoardCoil Switch side of 48 Frame HVAC Motor PC Board

(Mounted on armature shaft)(Mounted on armature shaft)

2004 SMMA2004 SMMA 2020

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/DriveMotor/Drive

Radiated and Conducted Noise Measurements on Radiated and Conducted Noise Measurements on the 48 frame HVAC Motorthe 48 frame HVAC Motor

Radiated standards were FCC Class A 3m and CE standard Radiated standards were FCC Class A 3m and CE standard EN55022 Class A 3mEN55022 Class A 3m

Both the horizontal and vertical planes were measured in the Both the horizontal and vertical planes were measured in the teststests

Conducted noise standard was EN55022 Class AConducted noise standard was EN55022 Class A

2004 SMMA2004 SMMA 2121

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/DriveMotor/Drive

2004 SMMA2004 SMMA 2222

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/DriveMotor/Drive

2004 SMMA2004 SMMA 2323

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/DriveMotor/Drive

2004 SMMA2004 SMMA 2424

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/DriveMotor/Drive

2004 SMMA2004 SMMA 2525

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion MotorMotor

2004 SMMA2004 SMMA 2626

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion MotorMotor

ConclusionsConclusions The adjustable speed brushless repulsion motor eliminates the The adjustable speed brushless repulsion motor eliminates the

need for high frequency PWM drive inverters that produce need for high frequency PWM drive inverters that produce radiated and conducted energy and high frequency common-radiated and conducted energy and high frequency common-mode currents that might damage bearings. mode currents that might damage bearings.

2004 SMMA2004 SMMA 2727

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion MotorMotor

ConclusionsConclusions The adjustable speed brushless repulsion motor eliminates the The adjustable speed brushless repulsion motor eliminates the

need for high frequency PWM drive inverters that produce need for high frequency PWM drive inverters that produce radiated and conducted energy and high frequency common-radiated and conducted energy and high frequency common-mode currents that might damage bearings. mode currents that might damage bearings.

The problem of common-mode currents is eliminated because The problem of common-mode currents is eliminated because all the switching is done in a closed space on the armature.all the switching is done in a closed space on the armature.

2004 SMMA2004 SMMA 2828

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/DriveMotor/Drive

ConclusionsConclusions The adjustable speed brushless repulsion motor eliminates the The adjustable speed brushless repulsion motor eliminates the

need for high frequency PWM drive inverters that produce need for high frequency PWM drive inverters that produce radiated and conducted energy and high frequency common-radiated and conducted energy and high frequency common-mode currents that might damage bearings. mode currents that might damage bearings.

The problem of common-mode currents is eliminated because The problem of common-mode currents is eliminated because all the switching is done in a closed space on the armature.all the switching is done in a closed space on the armature.

The filtering requirement for the input power line is The filtering requirement for the input power line is eliminated.eliminated.

2004 SMMA2004 SMMA 2929

EMI and EMC Aspects of a Brushless Repulsion EMI and EMC Aspects of a Brushless Repulsion Motor/DriveMotor/Drive

ConclusionsConclusions The adjustable speed brushless repulsion motor eliminates the The adjustable speed brushless repulsion motor eliminates the

need for high frequency PWM drive inverters that produce need for high frequency PWM drive inverters that produce radiated and conducted energy and high frequency common-radiated and conducted energy and high frequency common-mode currents that might damage bearings. mode currents that might damage bearings.

The problem of common-mode currents is eliminated because The problem of common-mode currents is eliminated because all the switching is done in a closed space on the armature.all the switching is done in a closed space on the armature.

The filtering requirement for the input power line is reduced.The filtering requirement for the input power line is reduced. No filtering is needed for the space between the controller and No filtering is needed for the space between the controller and

the armature.the armature.

2004 SMMA2004 SMMA 3030

EMI and EMC Aspects of a Brushless EMI and EMC Aspects of a Brushless Repulsion Motor/DriveRepulsion Motor/Drive

ThankyouThankyouYour Questions PleaseYour Questions Please

Presented by DynaMotors, Inc.Presented by DynaMotors, Inc.