One form of a motor control device includes: a waveform generation unit and an amplifier that generate a drive voltage of a voice coil motor (VCM); a DC offset detection unit that detects a DC offset of the drive voltage; a stop control unit that stops application of the drive voltage to a motor coil when the detected DC offset exceeds an operation stop threshold; a temperature correction value setting unit that sets a temperature correction value corresponding to the DC offset when the detected DC offset is lower than the operation stop threshold; a thermistor that detects an ambient temperature; and a vibration level control unit that varies the drive voltage and controls an amplitude level based on the detected ambient temperature and the set temperature correction value.

The present invention provides a method and system for controlling the temperature of an electric motor by adjusting the electric losses in the motor. In an embodiment, the required load on the motor is determined and a first motor voltage is provided to meet the required load. A predetermined temperature set point for the motor is compared against the temperature of the motor and based on the temperature of the motor and the predetermined temperature set point, a secondary motor voltage is determined. The motor voltage may then be adjusted based on the calculated voltage and the motor load measurement adjusted based on the measured motor speed and actual motor voltage.

The present invention provides a method and system for controlling the temperature of an electric motor by adjusting the electric losses in the motor. In an embodiment, the required load on the motor is determined and a first motor voltage is provided to meet the required load. A predetermined temperature set point for the motor is compared against the temperature of the motor and based on the temperature of the motor and the predetermined temperature set point, a secondary motor voltage is determined. The motor voltage may then be adjusted based on the calculated voltage and the motor load measurement adjusted based on the measured motor speed and actual motor voltage.

A method for continuous condition monitoring of an electric motor having a rotor and a stator and at least two motor phases, wherein, a first energy loss is associated with the first motor phase and a second energy loss is associated with the second motor phase. The temperature during operation of the electric motor is determined by firstly carrying out a first temperature calculation in order to estimate a temperature of the first motor phase, the first temperature calculation incorporating an energy loss estimation, and a temperature estimation in which a temperature of the first motor phase depends on the estimated energy loss. A second temperature calculation in order to estimate a temperature of the second motor phase utilizes the first temperature value and an energy loss difference between the first and the second energy loss.

A method for continuous condition monitoring of an electric motor having a rotor and a stator and at least two motor phases, wherein, a first energy loss is associated with the first motor phase and a second energy loss is associated with the second motor phase. The temperature during operation of the electric motor is determined by firstly carrying out a first temperature calculation in order to estimate a temperature of the first motor phase, the first temperature calculation incorporating an energy loss estimation, and a temperature estimation in which a temperature of the first motor phase depends on the estimated energy loss. A second temperature calculation in order to estimate a temperature of the second motor phase utilizes the first temperature value and an energy loss difference between the first and the second energy loss.

A control unit executes first current control for controlling a d-axis current component and a q-axis current component of a current to be supplied to a motor, second current control for controlling the d-axis current component and the q-axis current component based on a heating value target value related to a heating value generated in the motor and setting a ratio of the d-axis current component to the q-axis current component to be different from the ratio in the first current control, and vibration suppression control to be executed when the second current control is executed, and adds a first periodic signal to the torque target value in the vibration suppression control. A phase of the first periodic signal is shifted from a phase in a waveform of an output torque of the motor output when the second current control is executed without executing the vibration suppression control.

A motor controller includes an atmospheric pressure sensor, a coil temperature sensor, and a voltage sensor configured to detect a voltage applied to a motor. The motor controller calculates a partial discharge inception voltage in accordance with the atmospheric pressure and the coil temperature, limits an output of the motor in response to the coil temperature exceeding a preset coil temperature upper limit value, and reduces the coil temperature upper limit value in response to a voltage exceeding the partial discharge inception voltage.

A propulsion system for a device includes an electric motor configured to generate torque to propel the device. The electric motor includes a stator and a rotor with one or more permanent magnets. A controller is in communication with the electric motor and has recorded instructions for a method for minimizing demagnetization in the one or more permanent magnets. The controller is adapted to select a starting point and an intermediate point on a current trajectory in a stator current graph. The controller is adapted to obtain a final point on the stator current trajectory based on a comparison of the intermediate point and a predetermined voltage limit. A demagnetized torque capability is generated based on the final point on the current trajectory.

A method and equipment (apparatus) for estimating motor parameters includes: receiving an operating parameter of an electric motor, estimating an estimated first motor parameter based on the operating parameter and on an initially determined second motor parameter and estimating an estimated second motor parameter based on the operating parameter and on an initially determined first motor parameter. The equipment (apparatus) and the method further include estimating a revised estimated second motor parameter based on the estimated first motor parameter and on the operating parameter, and estimating a revised estimated first motor parameter based on the estimated second motor parameter and on the operating parameter.

A cooperative control method for an energy conversion apparatus is disclosed. The cooperative control method includes: acquiring a target heating power, a target driving power, and a target charging and discharging power; acquiring a first heating power of a motor coil according to the target charging and discharging power; acquiring a second heating power of the motor coil according to the target driving power; adjusting a first quadrature axis current and a first direct axis current to a target quadrature axis current and a target direct axis current when a difference between a sum of the first heating power and the second heating power and the target heating power is not within a preset range, to cause the difference between the sum of the first heating power and the second heating power and the target heating power to be within the preset range; and acquiring a sampling current value on each phase coil and a motor rotor position, and calculating a duty cycle of each phase bridge arm in a reversible pulse width modulation (PWM) rectifier.