A motor drive that outputs a sinusoidal waveform utilizes power switching devices operable at high switching frequencies. The switching devices may be operated, for example, between twenty kilohertz and one megahertz. A first filter is included at the output of the motor drive which has a bandwidth selected to attenuate voltage components at the output which are at the switching frequency or multiples thereof such that the output voltage waveform is generally sinusoidal. Additional filtering is included within the motor drive to establish a circulation path for common mode currents within the motor drive. Further, a shield is provided adjacent to those components within the motor drive that may experience voltage or current waveforms at the switching frequency or multiples thereof to cause radiated emissions to establish eddy currents within the EMI shield rather than passing through the shield into the environment.

A motor drive that outputs a sinusoidal waveform utilizes power switching devices operable at high switching frequencies. The switching devices may be operated, for example, between twenty kilohertz and one megahertz. A first filter is included at the output of the motor drive which has a bandwidth selected to attenuate voltage components at the output which are at the switching frequency or multiples thereof such that the output voltage waveform is generally sinusoidal. Additional filtering is included within the motor drive to establish a circulation path for common mode currents within the motor drive. Further, a shield is provided adjacent to those components within the motor drive that may experience voltage or current waveforms at the switching frequency or multiples thereof to cause radiated emissions to establish eddy currents within the EMI shield rather than passing through the shield into the environment.

A damping control device for an electric vehicle including a motor and a transmission in a drive system between the motor and a drive wheel includes a detector, a bandpass filter, first to third calculators, and a controller. The detector detects a rotation speed of the motor. The bandpass filter passes a vibration component included in the detected motor rotation speed, in a resonance frequency band of the drive system. The first calculator calculates a damping torque for damping resonance of the drive system with a motor torque, based on the passed vibration component. The second calculator calculates, as a damping torque offset value, an average value of the calculated damping torque for a predetermined time. The third calculator calculates a target damping torque. The controller controls a drive state of the motor.

A damping control device for an electric vehicle including a motor and a transmission in a drive system between the motor and a drive wheel includes a detector, a bandpass filter, first to third calculators, and a controller. The detector detects a rotation speed of the motor. The bandpass filter passes a vibration component included in the detected motor rotation speed, in a resonance frequency band of the drive system. The first calculator calculates a damping torque for damping resonance of the drive system with a motor torque, based on the passed vibration component. The second calculator calculates, as a damping torque offset value, an average value of the calculated damping torque for a predetermined time. The third calculator calculates a target damping torque. The controller controls a drive state of the motor.

A method for controlling a synchronous double stator electric machine. A first stator and a first set of magnetic poles on a common rotor forms a first electric machine. A second stator and a second set of magnetic poles on the rotor forms a second electric machine. The first electric machine and the second electric machine is shifted mechanically by a predetermined angle. An electrical shift is produced to the control of at least the mechanically shifted electric machine with a respective frequency converter in order to at least partly compensate for the mechanical shift in the mechanically shifted electric machine.

A method for controlling a synchronous double stator electric machine. A first stator and a first set of magnetic poles on a common rotor forms a first electric machine. A second stator and a second set of magnetic poles on the rotor forms a second electric machine. The first electric machine and the second electric machine is shifted mechanically by a predetermined angle. An electrical shift is produced to the control of at least the mechanically shifted electric machine with a respective frequency converter in order to at least partly compensate for the mechanical shift in the mechanically shifted electric machine.

A method and an apparatus for reducing noise of a switched reluctance motor, includes: supplying a PWM signal as a driving signal to a driving circuit of a switched reluctance motor; and varying a carrier frequency of the PWM signal as an operation period of the switched reluctance motor varies; if the switched reluctance motor changes phase, determining that the operation period of the switched reluctance motor varies.

A method and an apparatus for reducing noise of a switched reluctance motor, includes: supplying a PWM signal as a driving signal to a driving circuit of a switched reluctance motor; and varying a carrier frequency of the PWM signal as an operation period of the switched reluctance motor varies; if the switched reluctance motor changes phase, determining that the operation period of the switched reluctance motor varies.

An adaptive torque disturbance cancellation method and motor control system for rotating a load are described. The system has: (i) a speed controller for receiving a first input signal indicating a desired motor speed and, in response, for outputting a motor control signal; (ii) current sensing circuitry for sensing current through a motor that rotates in response to the speed controller; (iii) circuitry for storing, into a storage device, history data representative of the current through a motor when the motor operates to rotate the load; and (iv) circuitry for modifying the motor control signal in response to the history data.

An adaptive torque disturbance cancellation method and motor control system for rotating a load are described. The system has: (i) a speed controller for receiving a first input signal indicating a desired motor speed and, in response, for outputting a motor control signal; (ii) current sensing circuitry for sensing current through a motor that rotates in response to the speed controller; (iii) circuitry for storing, into a storage device, history data representative of the current through a motor when the motor operates to rotate the load; and (iv) circuitry for modifying the motor control signal in response to the history data.