A power converter includes: a converter circuit converting an alternating current to a direct current; a reactor electrically connected to one of output terminals of the converter circuit; a capacitor electrically connected to the other output terminal of the converter circuit and the reactor; and an inverter circuit electrically connected to the capacitor converting the direct current to an alternating current. The capacitor is a film capacitor. The capacitor and the reactor are mounted on an identical circuit board.

A momentary-voltage-drop compensation apparatus interconnecting a power system and a DC power supply to a load. The apparatus includes a system interconnection switch connected between the power system and the load, a first power converter that performs DC-AC conversion to DC power of the DC power supply, a second power converter that includes a first terminal connected to the first power converter and the DC power supply, and a second terminal connected between the system interconnection switch and the power system, for performing AC-DC conversion to the AC power supplied from the power system, and a control unit that is connected to the first power converter, and is configured to control, in response to a voltage drop in the power system, the first power converter to output a zero-phase current, a current value of which is no larger than that of a current flowing through the system interconnection switch.

A momentary-voltage-drop compensation apparatus interconnecting a power system and a DC power supply to a load. The apparatus includes a system interconnection switch connected between the power system and the load, a first power converter that performs DC-AC conversion to DC power of the DC power supply, a second power converter that includes a first terminal connected to the first power converter and the DC power supply, and a second terminal connected between the system interconnection switch and the power system, for performing AC-DC conversion to the AC power supplied from the power system, and a control unit that is connected to the first power converter, and is configured to control, in response to a voltage drop in the power system, the first power converter to output a zero-phase current, a current value of which is no larger than that of a current flowing through the system interconnection switch.

Disclosed is a power conversion device having an AC conversion unit and a control unit that controls the AC conversion unit. The power conversion device also has: a temperature detection unit that outputs temperature data of the power conversion device; a current detection unit that outputs current data of an output of the AC conversion unit; a storage unit that stores specification data indicating a relationship between a rated current and a temperature specification and temperature data output by the detection unit; an overload protection unit that outputs a shutdown command to the control unit on the basis of the rated current and the current data output by the current detection unit; and a rating determination unit that acquires specification data and temperature data from the storage unit, determines a rated current corresponding to the acquired temperature data on the basis of the acquired specification data, and outputs the determined rated current to the overload protection unit.

A method for operating a brushless electric motor of a motor vehicle, particularly an electromotive refrigerant compressor, with two sub-motors arranged in sections and each comprising n-phases, by means of a converter corresponding to the number of phases of the electric motor. On the basis of a performance requirement, first switching points are determined for the n-phases, of one of the sub-motors, and on the basis of the performance requirement, second switching points are determined for the n-phases of the other sub-motor. The second switching points are shifted by a first phase angle and the converter is controlled on the basis of the first switching points and the second switching points. The first phase angle is selected such that a resulting current flow over the converter is smaller than a first threshold value. A unit of a motor vehicle, comprising a brushless electric motor is also disclosed.

A power converter includes: a converter circuit converting an alternating current to a direct current; a reactor electrically connected to one of output terminals of the converter circuit; a capacitor electrically connected to the other output terminal of the converter circuit and the reactor; and an inverter circuit electrically connected to the capacitor converting the direct current to an alternating current. The capacitor is a film capacitor. The capacitor and the reactor are mounted on an identical circuit board.

This disclosure provides systems, methods, and apparatus for multi-level inverters. A hybrid binary cascaded multilevel inverter (BCMLI) is discussed that includes a plurality of H-bridge cells connected in a cascaded formation. DC input voltages of some of the H-bridge cells are provided by DC voltage sources. But inputs of other H-bridge cells coupled with capacitors instead. The H-bridge cells are operated to provide an AC output voltage at the output terminals of the inverter. One or more floating capacitor voltage controllers are used to vary one or more switching instances of the H-bridge cells such that a desirable level or charge is maintained across the one or more capacitors coupled with the input terminals of the H-bridge cells.

This disclosure provides systems, methods, and apparatus for multi-level inverters. A hybrid binary cascaded multilevel inverter (BCMLI) is discussed that includes a plurality of H-bridge cells connected in a cascaded formation. DC input voltages of some of the H-bridge cells are provided by DC voltage sources. But inputs of other H-bridge cells coupled with capacitors instead. The H-bridge cells are operated to provide an AC output voltage at the output terminals of the inverter. One or more floating capacitor voltage controllers are used to vary one or more switching instances of the H-bridge cells such that a desirable level or charge is maintained across the one or more capacitors coupled with the input terminals of the H-bridge cells.

A converter circuit converts AC electric power into DC power. An inverter circuit converts the DC power into AC power. A capacitor is connected in parallel to each of the converter circuit and the inverter circuit between these circuits. The capacitor allows variation of an output voltage from the converter circuit, and absorbs variation of an output voltage from the inverter circuit due to a switching operation. An overvoltage protection circuit includes a resistor and a semiconductor element connected in series to each other. The overvoltage protection circuit is connected in parallel to the capacitor to protect the inverter circuit from an overvoltage. First and second control units respectively control the inverter circuit and the overvoltage protection circuit.

A converter circuit converts AC electric power into DC power. An inverter circuit converts the DC power into AC power. A capacitor is connected in parallel to each of the converter circuit and the inverter circuit between these circuits. The capacitor allows variation of an output voltage from the converter circuit, and absorbs variation of an output voltage from the inverter circuit due to a switching operation. An overvoltage protection circuit includes a resistor and a semiconductor element connected in series to each other. The overvoltage protection circuit is connected in parallel to the capacitor to protect the inverter circuit from an overvoltage. First and second control units respectively control the inverter circuit and the overvoltage protection circuit.