A method, a control circuit, and a power converter arrangement are disclosed. The method includes: coupling three power converters (1, 2, 3) with each other; connecting each of the three power converters (1, 2, 3) to a 3-phase power source (4) configured to provide three supply voltages (Ua, Ub, Uc); and regulating a respective input signal (V1, V2, V3; I1, I2, I3) of each of the three power converters (1, 2, 3) dependent on a common mode signal (Scm).

Provided is an active filter circuit connected to a power-receiving terminal of a power line for an alternating-current power supplied to a power converter device from an alternating-current power grid or a direct-current power source interconnected with the alternating-current power grid, or for a direct-current power supplied from the direct-current power source for reducing a harmonic component of a conduction noise propagating to the power line and outputting the reduced harmonic; and a controller for monitoring a variation in the state of an input power entering a power source module for generating drive power for an active element constituting the active filter circuit, or a variation in the state of the drive power supplied from the power source module, and diagnosing an abnormality of a circuit operation for a circuit including the active element of the active filter circuit therein.

A control method of a three-phase multi-level inverter includes: determining a modulation ratio based on output of the three-phase multi-level inverter, where the modulation ratio indicates a ratio of an amplitude value of a sinusoidal modulation wave in pulse width modulation to an amplitude value of a carrier; generating, based on the modulation ratio and a modulation ratio threshold, a common-mode voltage regulation signal for regulating a common-mode voltage in phase voltages of the three-phase multi-level inverter; adding the common-mode voltage regulation signal and a differential-mode voltage regulation signal for regulating a differential-mode voltage in the phase voltages of the three-phase multi-level inverter to obtain a composite regulation signal, where the composite regulation signal is presented as a modulation wave for discontinuous pulse width modulation (DPWM); and generating, based on the composite regulation signal, drive signals for controlling switches of phases of the three-phase multi-level inverter.

An AC/DC converter stage for a converter system with an input series structure. The AC/DC converter stage includes two input terminals for inputting an AC input voltage and at least a first circuit branch with at least two switches that are electrically connected in series at a first connection point, where a first input terminal of the two input terminals is electrically connected to the first connection point of the first circuit branch. At least one first electrical storage provides a DC output voltage and is electrically connected in parallel to the first circuit branch. At least one controllable bidirectional switch is electrically connected between the two input terminals.

Systems and methods for power conversion are described. Symmetric topologies and modulation schemes are described that may reduce common-mode noise. For example, a system may include a transformer including a first secondary winding and a second secondary winding; a rectifier, including a set of switches, that connects taps of the first secondary winding and the second secondary winding to a first terminal and a second terminal, wherein the rectifier is symmetric with respect to the first secondary winding and the second secondary winding; a battery connected between the first terminal and the second terminal; and a processing apparatus that is configured to control the set of switches to rectify a multilevel voltage signal on the transformer, including: selecting a modulation scheme from among two or more modulation schemes based on a measured voltage level of the battery.

An active common mode filter is configured to be positioned between a power supply and a switching converter-device/load for reducing common mode noise. The active common mode filter includes an active capacitor that has a sensing stage including one or more sensing capacitors, an amplifying stage including a common collector amplifier for mitigating an input voltage divider effect coupled to a common emitter amplifier for providing high gain, and an injection stage including one or more injection capacitors. Depending on the required attenuation in different applications, a multistage active common mode filter may be formed with a necessary number of stages, each stage including an active capacitor and an inductor.

Even when a grounding capacitor is included at either end of a common mode coil, there is noise that flows from a load into a metal frame, and there is a need to restrict an amount of noise propagating to a system power supply. Because of this, a noise loop is formed of a rectifier circuit, an inverter, a first electrical wire that connects a positive polarity side of the rectifier circuit and the inverter, a second electrical wire that connects a negative polarity side of the rectifier circuit and the inverter, a ground wire terminal that can connect a load connected to an output terminal or the inverter, and a conductive plate that connects at least one or the first electrical wire and second electrical wire and the ground wire terminal.

The power conversion device includes: a main circuit having first and second wiring layers formed respectively on both surfaces of a base board, mounted parts mounted on the first and second wiring layers, and first and second GND layers formed respectively, between external- and internal-layer portions of the base board and in regions corresponding to the mounted parts each being a mounted part which forms a circuit other than a circuit having an inductance component as a lumped constant, and to the first and second wiring layers; and a cooler attached to the base board by means of fixing screws through a first through-hole created in an end portion of the board; wherein the first and second GND layers are each formed so that creepage distance is created around a second through-hole in which a lead insertion part that mutually connects the first and second wiring layers is inserted.

An AC-DC converter may include three phase terminals, two DC terminals, a first converter stage to convert between an AC current at the phase terminals and a first DC current at the first and second intermediate nodes, a second converter stage operable to convert between a first DC signal at third and fourth intermediate nodes and a second DC signal at the DC terminals, a first filter stage comprising a capacitor network having a star-point, a DC link connecting the first intermediate node to the third intermediate node and the second intermediate node to the fourth intermediate node. The second converter stage includes a middle voltage node between the DC terminals and a boost circuit having a midpoint node at the same electrical potential as the middle voltage node. The DC link includes a common mode filter having a common mode capacitor connecting the middle voltage node to the star-point.

In accordance with at least one aspect of this disclosure, a method for pulse width modulation control includes resolving a reference vector for any number of active space vectors to determine a voltage offset for the reference vector, adding the voltage offset to each active vector to determine a modified modulated signal to be added to a carrier signal, and controlling, with a control module, a switching circuit based at least in part on the modified carrier signal.