Conventionally, there is a problem that switching loss of an inverter increases in a case where a change such as improvement in a switching frequency is involved. The battery voltage E and the torque command T* are input to the first current command generation unit 111. The battery voltage E, the torque command T*, and a voltage utilization rate obtained by dividing a line voltage effective value by a battery voltage (DC voltage) are input to a second current command generation unit 112. A magnet temperature Tmag of a rotor magnet is input to a current command selection unit 113, and a current command output from the first current command generation unit 111 is selected in normal operation, and the second current command generation unit 112 is selected in a case where the magnet temperature exceeds a predetermined value. The second current command generation unit 112 is configured not to obtain the voltage utilization rate of 0.3 to 0.4.

A method for actuating an electrical circuit arrangement including at least one switching element. The switching element is actuated by a driver circuit as a function of switching-signal information for switch-on and switch-off. The switching-signal information is continuously determined and a switch-on period and signal position information are specified respectively for at least one switching-signal time window with a fixed duration. The position of the switch-on signal within the switching-signal time window is specified by the signal position information for a switch-on signal that results from a switch-on period that is less than the duration of the switching-signal time window.

The invention relates to a method for operating a wind turbine which comprises a power generator, a generator side converter, a grid side converter, a DC link electrically connected to an output of the generator side converter and an input of the grid side converter. The method comprises monitoring a wind turbine signal for detection of an operational condition which requires an increase of an output voltage of the grid side converter, upon detection of the operational condition, initiate an over-modulation mode wherein the grid side converter is operated with a modulation index in an over-modulation range, and upon the detection of the operational condition, initiate a DC-voltage adjustment mode wherein the a DC-voltage of the DC link is increased from a first voltage level towards a second voltage level.

A three-phase regenerative drive configured for operation from a single phase alternating current (AC) power source, the three-phase regenerative drive including a three-phase converter having inputs for connection to a single-phase AC source, the three-phase converter having three phase legs, a three-phase inverter for connection to a motor, the three phase inverter configured to provide three phase command signals to the motor, and a DC bus connected between the three-phase converter and the three-phase inverter. A first phase leg of the three-phase converter and a second phase leg of the three-phase converter are employed to direct current from the single-phase AC source to the DC Bus and a third phase leg of the three phase legs of the three-phase converter returns current to a return of the AC source.

Examples include a variable speed drive and method for controlling such variable speed drive driving an electric motor. The variable speed drive includes an inverter and is able to detect when a specific component (IGBT or freewheeling diode) of a specific switch of the inverter crosses a predetermined voltage threshold. An example method allows determining a state of a specific component based on the detection of the crossing.

A method of operating a motor includes providing an electric system coupled with the motor, the electric system including parallel inverter legs; subjecting the motor to a first interleaving angle when the electric system is under a first condition; and subjecting the motor to a second interleaving angle different from the first interleaving angle when the electric system is under a second condition; wherein the steps of subjecting the motor to the first interleaving angle and subjecting the motor to the second interleaving angle occur within continuous operation of the electric system and the motor.

A control device (8) for an inverter (2) that feeds an electric machine (3), wherein the control device (8) is configured to provide pulse-width modulated switching signals (15) with a carrier frequency to drive switching elements (12) of the inverter (2), wherein the control device (8) is configured to determine the carrier frequency depending on operating point information that describes an operating point defined by a rotation speed and a torque of the electric machine (3) and, as the rotation speed increases and the magnitude of the torque falls, to increase the carrier frequency within an operating region (22) that extends within a rotation speed interval with a lower rotation speed limit (23) differing from zero and with an upper rotation speed limit (24) lying in a power-limiting operating region (21) or field-weakening operating region.

A controller includes a first processor for a first power inverter. Computer-readable media is configured to store computer-executable instructions configured to cause the first processor to: generate a first clock signal and a second clock signal; identify a pulse width modulation method of the first power inverter and a pulse width modulation method of a second power inverter; identify and compare a switching frequency of the first power inverter and a switching frequency of the second power inverter; determine an optimized phase shift between the first power inverter and the second power inverter responsive to the pulse width modulation method of the first power inverter and the pulse width modulation method of the second power inverter and the switching frequency of the first power inverter and the switching frequency of the second power inverter; and synchronize the optimized phase shift between the first power inverter and the second power inverter. A second processor for the second power inverter is configured to receive the second clock signal.

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.

A power system including a power converter system and an electric machine is provided. In one aspect, the power converter system has first and second switching elements. The electric machine includes a first multiphase winding electrically coupled with the first switching elements and a second multiphase winding electrically coupled with the second switching elements. The first and second multiphase windings are arranged and configured to operate electrically opposite in phase with respect to one another. One or more processors control the first switching elements to generate first pulse width modulated (PWM) signals based on received voltage commands to render a first common mode signal and also control the second switching elements to generate second PWM signals based on received voltage commands to render a second common mode signal. The rendered first and second common mode signals have the same or similar waveform with opposite polarity with respect to one another.