The invention determines at least one of the angular speed and the angular position of a rotor of an electric machine through determination of the harmonics, using a closed loop comprising a harmonic observer, phase difference correction and a first phase-locked loop that estimates the position of the rotor.

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.

In a method for operating a controllable converter with an intermediate circuit capacitor, the control behavior can be improved by transmitting, depending on an intermediate circuit voltage applied to the intermediate circuit capacitor, an additional power component via the controllable converter such that the electric current that is generated by the controllable converter for the additional power component counteracts an oscillation of the intermediate circuit voltage. The additional power component is transmitted by the controllable converter to a connected motor as a pulsating additional torque. Also described is a controllable converter with a control unit for carrying out a method, wherein the controllable converter has semiconductors that can be switched off, and an intermediate circuit capacitor designed as a film-type capacitor.

This power conversion device includes: a current detection unit for detecting current flowing through a rotary electric machine; a switching pattern determination unit for determining a switching pattern on the basis of the detected current, a current prediction value, a current command value, and a current harmonic command value; and a power conversion unit for outputting AC power to the rotary electric machine in accordance with the switching pattern, wherein the switching pattern determination unit determines the switching pattern so that the current value follows the current command value and the current harmonic becomes equal to or smaller than a limit value.

Provided is a method for controlling an electric generator of a wind turbine. The method includes varying an amplitude and/or phase angle of an harmonic current of said electric generator, while said electric generator is rotating, in particular at a known condition, measuring a signal indicative of generator vibration after and/or during varying said amplitude and/or phase angle, repeating said varying and said measuring until a predetermined requirement is met, evaluating an operating point for said electric generator by using said measured signals indicative of generator vibration in order to reduce a ripple torque of said generator, and controlling a current, in particular said harmonic current, of said electric generator in order to meet said operating point.

A method for controlling operation of a rotary electric machine includes receiving, via a bandwidth-partitioning harmonic compensation regulator (HCR) of a controller, a commanded torque and rotational speed of the electric machine, and calculating, via the HCR in response to enabling conditions, a dq harmonic compensation current and a dq harmonic compensation voltage for one or more predetermined harmonic orders using the commanded torque and the rotational speed. The harmonic compensation current and voltage cancel torque ripple and current ripple in the one or more predetermined harmonic orders. The method may include injecting an acoustic tone at a predetermined harmonic order. The method additionally includes adding the dq harmonic compensation current and voltage to a dq current and voltage command, respectively, to generate adjusted dq current and voltage commands. The electric machine is then controlled using the adjusted dq current and voltage commands.

A system (110) and method of controlling a three-phase active harmonic filter (160) with a three-phase converter having inputs for connection to a three-phase AC source (112), the three-phase converter having three phase legs, each phase leg of the three phase legs of the three-phase converter includes a first switching device operably connected to a first power supply rail and a second switching device operably connected to a second supply rail, the three-phase converter operably connected to a controller. The controller is configured to determine an operating characteristic of the AHF and operable to control the first and second switching devices of each phase leg of the three phase legs with a first PWM strategy, compare the operational characteristic of the AHF to a selected threshold, and employ a second PWM strategy if the operational characteristic exceeds a selected threshold.

A system (110) and method of controlling a three-phase active harmonic filter (160) with a three-phase converter having inputs for connection to a three-phase AC source (112), the three-phase converter having three phase legs, each phase leg of the three phase legs of the three-phase converter includes a first switching device operably connected to a first power supply rail and a second switching device operably connected to a second supply rail, the three-phase converter operably connected to a controller. The controller is configured to determine an operating characteristic of the AHF and operable to control the first and second switching devices of each phase leg of the three phase legs with a first PWM strategy, compare the operational characteristic of the AHF to a selected threshold, and employ a second PWM strategy if the operational characteristic exceeds a selected threshold.

An on-vehicle motor-driven compressor includes an inverter device having a noise reducer. The noise reducer includes a common mode choke coil. The common mode choke coil includes an annular core, first and second windings wound around the core, the second winding being spaced apart from and opposed to the first winding, an annular conductor that extends over the first winding and the second winding and covers the core, and an insulating layer located between an inner circumferential surface of the conductor and outer surfaces of the first winding and the second winding. The conductor is tubular and belt-shaped. The core includes an exposed portion that is not covered by the conductor. The insulating layer is tubular and belt-shaped. An entirety of the conductor is arranged within a range between opposite ends of the insulating layer.

A control circuit of an electric motor includes a filtering device in order to filter high frequencies likely to produce perturbing electromagnetic radiation when the electric motor is driven. To this end, the filtering device includes one or more filtering capacitors branched off from a power bridge driving the electric motor, wherein at least a proportion of the filtering capacitors is of a polymer-hybrid type in order to improve dynamic performance of the filtering device and to reduce its size. A motorized-fan unit for motor vehicles including such a control circuit is also disclosed.