An apparatus and a method for inverter control are disclosed. A method according to an embodiment of the present disclosure comprises: discretizing, in a continuous time domain, a voltage equation for a motor in a stationary coordinate system in which a zero-order hold and time delay is reflected; and determining a voltage equation for the motor in a synchronous coordinate system in a discrete time domain by reflecting the position and speed of a rotor of the motor.

A motor controller circuit having a stable speed controlling mechanism is provided. A duty cycle determining circuit determines duty cycles of the plurality of waveforms respectively of the first waveform signals within each of a plurality of time intervals to output a duty cycle instructing signal, according to a target working period corresponding to a target rotational speed. A signal generating circuit outputs the plurality of first waveform signals according to the duty cycle instructing signal, and outputs a second waveform signal. A motor control circuit outputs a plurality of on-time signals according to the plurality of first waveform signals and the second waveform signal. A motor driving circuit is controlled to operate and drive a motor to rotate according to the plurality of on-time signals.

A rotation calculation unit calculates a rotation speed of a virtual generator on the basis of a rotor model to simulate driving of the virtual generator and calculates the rotation speed of the virtual generator. A target power determination unit determines target values of active power and reactive power of an inverter on the basis of the calculated rotation speed. A command generation unit generates a control command for the inverter on the basis of the determined target values of the active power and the reactive power.

Aspects of the disclosure include a power system comprising at least one three-wire active harmonic filter (AHF) configured to be coupled to, and provide compensation current to, a three-phase load, at least one four-wire AHF configured to be coupled to, and provide compensation current to, the three-phase load, and a controller configured to determine a total compensation current to provide to the three-phase load, the total compensation current including a zero component and a non-zero component, determine an output capacity of the at least one three-wire AHF and the at least one four-wire AHF, calculate a current-compensation ratio based on the output capacity of the at least one three-wire AHF and the at least one four-wire AHF, and control the at least one four-wire AHF to provide at least a portion of the non-zero component of the total compensation current to the three-phase load based on the current-compensation ratio.

A power conversion system according to the present disclosure includes a plurality of power converters for performing power conversion on AC power and is connected to a power grid of multi-phase power that is a combination of multiple alternating current sources with mutually different phases. Each of the plurality of power converters includes a power converter circuit, a setting unit, and a control circuit. The power converter circuit performs power conversion between either DC power or AC power and AC power supplied from any of the multiple alternating current sources. The setting unit selects one of the multiple alternating current sources as a target of the power conversion to be performed by the power converter circuit. The control circuit controls operation of the power converter circuit in accordance with selection made by the setting unit.

A control device for a power converter that can suppress oscillation of an output voltage of the power converter. The control device for the power converter includes an overvoltage detector configured to detect an overvoltage on an output side of the power converter and a controller configured to, when the overvoltage on the output side of the power converter is detected by the overvoltage detector, perform gate block after reducing a current command value given to the power converter. With the configuration, when the overvoltage on the output side of the power converter is detected, the control device performs the gate block after reducing the current command value given to the power converter. Accordingly, it is possible to suppress oscillation of an output voltage of the power converter.

According to at least one aspect of the disclosure, an inverter is provided comprising an input configured to receive input DC power from a DC source, an output configured to provide output AC power to a load, a plurality of DC rails coupled to the input and configured to receive the input DC power from the DC source, a plurality of switches coupled between the plurality of DC rails and configured to convert the input DC power into the output AC power, each switch of the plurality of switches having a parasitic capacitance, and at least one ZVS network coupled across at least two switches of the plurality of switches, the ZVS network including at least two inductors configured to resonate with the parasitic capacitance of at least one switch of the plurality of switches to provide soft switching of at least one switch of the plurality of switches.

The drive controller for the electric motor according to the present invention comprises two drive control systems for two winding sets of the electric motor, each drive control system includes a control circuit, an inverter, a power supply connector and a ground connector, the two control circuits are connected to an internal common ground, each rectifying element that passes a current from the common ground to each ground connector is provided in a line that connects the ground connector and the common ground, each current detection element is provided in a line that connects each positive power supply and a line between the rectifying element and the ground connector, and whether an open fault has occurred in the ground connector is diagnosed based on the voltage that is applied to the current detection element.

An inverter has at least three phases for supplying current to an electrical machine. The inverter also has a control unit and at least one power output stage connected to the control unit on an input side. The control unit is configured to generate pulse-width-modulated control signals for activating the power output stage. The inverter further has a heat sink and, for each phase, an intermediate circuit capacitor and a semiconductor switch half bridge. The heat sink has a flat thermal contact surface. The thermal contact surface is connected in a thermally conductive manner to the control unit and to the semiconductor switch half bridges. The heat sink has a recess for each of the intermediate circuit capacitors, and the intermediate circuit capacitors are each arranged in one of the recesses in the heat sink.

Described herein are active rectification methods and systems for a rectifier of a wireless power system. Exemplary methods can include detecting, by a zero-crossing detector, one or more zero-crossings of a current at an input of the rectifier and determining a first delay time based on at least one wireless power system parameter and the zero-crossings. The methods can include generating first and second control signals for first and second switches of the rectifier, respectively, based on the first delay time; inserting a first dead time between the first control signal and the second control signal; and providing the first and second control signals to the first and second switches, respectively.