This disclosure is directed to systems and methods for controlling compressor motors, particularly varying the operation parameters of the motor to provide heat to a lubricant of the motor. The operation parameters include one or more of a pulse width modulation switching frequency, a pulse width modulation frequency switching pattern, or a torque/amp ratio of a drive of the compressor. The efficiency of the motor may be reduced to provide heat, with the heat improving lubricant quality and drive efficiency, to increase an overall efficiency of compressor operations. Methods may include determining a lubricant quality, and determining operational parameters that improve lubricant quality.

This disclosure is directed to systems and methods for controlling compressor motors, particularly varying the operation parameters of the motor to provide heat to a lubricant of the motor. The operation parameters include one or more of a pulse width modulation switching frequency, a pulse width modulation frequency switching pattern, or a torque/amp ratio of a drive of the compressor. The efficiency of the motor may be reduced to provide heat, with the heat improving lubricant quality and drive efficiency, to increase an overall efficiency of compressor operations. Methods may include determining a lubricant quality, and determining operational parameters that improve lubricant quality.

An electric motor, a power system, a control method, and an electric vehicle. The electric motor comprises a first N-phase winding set and a second N-phase winding set, wherein the first N-phase winding set and the second N-phase winding set are both used for being connected to a traction battery by means of a conversion module. When the traction battery starts to be heated, the first N-phase winding set and the second N-phase winding set are powered on. The direction of a magnetic field generated by the first winding set and the direction of a magnetic field generated by the second winding set have a phase difference, such that the magnetic fields counteract each other; and a magnetic field intensity in a stator winding of each phase is reduced, and an air-gap magnetic flux is also reduced, thereby alleviating the problems of electric motor heating and electric motor NVH.

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.

The embodiments of the present disclosure provide a control method, a device, a power system, and an electric vehicle. The method is applied to a motor controller of the power system. The power system further includes a power battery, a motor, and an inverter. The method includes: sending a first control signal to the inverter when a cell temperature of the power battery satisfies a preset heating condition for the power battery; where the first control signal is configured to control the inverter to convert an electricity provided by the power battery into an alternating current with a frequency changing randomly, and the alternating current with the frequency changing randomly is configured to supply power to the motor.

An electric drive unit includes a polyphase alternating current (AC) motor, an inverter. A motor controller employs field oriented controls to achieve torque and heat production objectives for the electric drive unit. Additional heat may be generated through inverter operation control.

A control device 60 includes: a PWM generation unit 63 that outputs a PWM drive signal to an inverter 40; and a torque limiting unit that outputs a post-limitation torque command to the PWM generation unit 63 based on a torque command from a higher-order control unit and a motor temperature. The torque limiting unit includes: a torque limiting factor calculation unit 61 that calculates a torque limiting factor based on the motor temperature; and a post-limitation torque calculation unit 62 that outputs the post-limitation torque command to the PWM generation unit 63 based on the torque command and the torque limiting factor. The torque limiting factor calculation unit 61 limits an output torque based on the motor temperature in a case where the motor temperature is higher than a predetermined temperature, and limits a torque to make the torque change more gently in a case where a rate of change over time in the motor temperature is larger than a predetermined value as compared with a case where the rate of change over time is equal to or smaller than the predetermined value.

A control device 60 includes: a PWM generation unit 63 that outputs a PWM drive signal to an inverter 40; and a torque limiting unit that outputs a post-limitation torque command to the PWM generation unit 63 based on a torque command from a higher-order control unit and a motor temperature. The torque limiting unit includes: a torque limiting factor calculation unit 61 that calculates a torque limiting factor based on the motor temperature; and a post-limitation torque calculation unit 62 that outputs the post-limitation torque command to the PWM generation unit 63 based on the torque command and the torque limiting factor. The torque limiting factor calculation unit 61 limits an output torque based on the motor temperature in a case where the motor temperature is higher than a predetermined temperature, and limits a torque to make the torque change more gently in a case where a rate of change over time in the motor temperature is larger than a predetermined value as compared with a case where the rate of change over time is equal to or smaller than the predetermined value.

An energy conversion device is provided. The energy conversion device includes a reversible pulse-width modulation (PWM) rectifier (102) and a motor coil (103). The motor coil (103) includes L sets of winding units, and each set of winding unit is connected with the reversible PWM rectifier (102), where L≥2 and is a positive integer. At least two sets of heating circuits of a to-be-heated device are formed by an external power supply (100), the reversible PWM rectifier (102), and the winding units in the motor coil (103). The energy conversion device controls the reversible PWM rectifier (102) according to a control signal, so that a current outputted from the external power supply (100) flows through at least two sets of winding units in the motor coil (103) to generate heat, and cause a vector sum of resultant current vectors of the at least two sets of the winding units on a quadrature axis of a synchronous rotating reference frame based on rotor field orientation of the motor to be zero.

A method for operating an electric motor is provided which includes power electronics of a drive system operating an electric motor of the drive system using clock signals, as well as power electronics for a drive system and a vehicle.