Abstract: A power conversion device includes: a switching circuit; a signal generator to generate a switching signal of a switching element based on a first instruction value; a current controller to generate a second instruction value based on a deviation between a current target value and the current flowing through the switching circuit such that the current flowing through the switching circuit approaches the current target value; an operation mode detector to detect an operation mode based on the first instruction value; and a compensator to adjust the second instruction value so as to compensate a gain between the deviation and an amount of a change in the current of the switching circuit. The compensator adjusts the second instruction value so as to suppress a change in the gain based on the operation mode, and outputs the first instruction value.

Abstract: A charging device for charging a storage battery mounted on an electric vehicle includes: a first relay to generate a communication start signal for causing communication between the charging device and the electric vehicle to be started; a cable including a connector for connection to a plug of the electric vehicle at one end to electrically connect the charging device and the electric vehicle; a signal line included in the cable and connected to the first relay; a power supply circuit to pass a current to the signal line when the connector is connected to the plug; a current detection circuit to detect a current flowing in the signal line; and a controller to control the first relay and start the communication when the current detection circuit detects the current.

Abstract: A charging device for charging a storage battery mounted on an electric vehicle includes: a first relay to generate a communication start signal for causing communication between the charging device and the electric vehicle to be started; a cable including a connector for connection to a plug of the electric vehicle at one end to electrically connect the charging device and the electric vehicle; a signal line included in the cable and connected to the first relay; a power supply circuit to pass a current to the signal line when the connector is connected to the plug; a current detection circuit to detect a current flowing in the signal line; and a controller to control the first relay and start the communication when the current detection circuit detects the current.

Abstract: A temperature estimation device calculates a first estimation temperature of a reactor on the basis of a reference estimation temperature to which a first lag period is provided and outputs from a temperature change amount calculation unit to which a second lag period is provided, predicts a second temperature change amount of the reactor over a predetermined period on the basis of the first estimation temperature, and then predicts a second estimation temperature of the reactor.

Abstract: A temperature estimation device calculates a first estimation temperature of a reactor on the basis of a reference estimation temperature to which a first lag period is provided and outputs from a temperature change amount calculation unit to which a second lag period is provided, predicts a second temperature change amount of the reactor over a predetermined period on the basis of the first estimation temperature, and then predicts a second estimation temperature of the reactor.

Abstract: An inverter device, a motor driving device, a refrigerating air conditioner, and a power generation system, which can reduce the recovery loss thereof, are obtained. A plurality of arms that can conduct and block current are provided. At least one of the plurality of arms includes: a plurality of switching elements each having a parasitic diode and being connected in series with each other; and a reverse current diode connected in parallel with the plurality of switching elements.

Abstract: An inverter device, a motor driving device, a refrigerating air conditioner, and a power generation system, which can reduce the recovery loss thereof, are obtained. A plurality of arms that can conduct and block current are provided. At least one of the plurality of arms includes: a plurality of switching elements each having a parasitic diode and being connected in series with each other; and a reverse current diode connected in parallel with the plurality of switching elements.

Abstract: An inverter device, a motor driving device, a refrigerating air conditioner, and a power generation system, which can reduce the recovery loss thereof, are obtained. A plurality of arms that can conduct and block current are provided. At least one of the plurality of arms includes: a plurality of switching elements each having a parasitic diode and being connected in series with each other; and a reverse current diode connected in parallel with the plurality of switching elements.

Abstract: A grounding wire from a commercial power system is connected to a series-connection end of a series connection between two capacitors connected in series between a positive electrode and a negative electrode. A current detector monitors an output current of an inverter unit in which four switching elements and two diodes convert voltages at both ends of the series circuit of the capacitors at three levels. An operation control circuit controls a generation of a PWM signal to be applied to the four switching elements, to minimize a difference between a current value detected by the current detector and a target current value.

Abstract: A system interconnection inverter includes a step-up converter and an inverter. Moreover, the system interconnection inverter includes a short-circuit current-interrupting diode with a cathode connected to an input terminal of a negative bus, a semiconductor switch connected to an anode of the short-circuit current-interrupting diode, a semiconductor switch drive circuit that drives the semiconductor switch, a semiconductor switch-off circuit that turns off the semiconductor switch drive circuit when negative power is applied such that electric current flows from a cathode toward an anode of the input terminal, and a control circuit that controls the semiconductor switch drive circuit.

Abstract: In a zero-phase current detecting apparatus, a feedback loop is made up of a pulse generating unit, a current detecting unit, a peak detecting unit, an adding unit, and a current regulating unit. The adding unit outputs a difference between a target value and a peak value detected by the peak detecting unit. A zero-phase current is detected based on the difference output from the adding unit as a result of regulation of the peak value so as to be the target value in the adding unit.

Abstract: A first booster circuit and a second booster circuit include input capacitors, reactors, diodes, switch elements, and output capacitors, and are arranged to be symmetric to each other on a positive side and a negative side. The reactors are magnetically coupled to each other. With such configuration, the switch elements are on/off controlled simultaneously based on terminal voltages of the input capacitors and the output capacitors.

Abstract: In a zero-phase current detecting apparatus, a feedback loop is made up of a pulse generating unit, a current detecting unit, a peak detecting unit, an adding unit, and a current regulating unit. The adding unit outputs a difference between a target value and a peak value detected by the peak detecting unit. A zero-phase current is detected based on the difference output from the adding unit as a result of regulation of the peak value so as to be the target value in the adding unit.

Abstract: A first booster circuit and a second booster circuit include input capacitors, reactors, diodes, switch elements, and output capacitors, and are arranged to be symmetric to each other on a positive side and a negative side. The reactors are magnetically coupled to each other. With such configuration, the switch elements are on/off controlled simultaneously based on terminal voltages of the input capacitors and the output capacitors.

Abstract: A system interconnection inverter includes a step-up converter and an inverter. Moreover, the system interconnection inverter includes a short-circuit current-interrupting diode with a cathode connected to an input terminal of a negative bus, a semiconductor switch connected to an anode of the short-circuit current-interrupting diode, a semiconductor switch drive circuit that drives the semiconductor switch, a semiconductor switch-off circuit that turns off the semiconductor switch drive circuit when negative power is applied such that electric current flows from a cathode toward an anode of the input terminal, and a control circuit that controls the semiconductor switch drive circuit.

Abstract: A grounding wire from a commercial power system is connected to a series-connection end of a series connection between two capacitors connected in series between a positive electrode and a negative electrode. A current detector monitors an output current of an inverter unit in which four switching elements and two diodes convert voltages at both ends of the series circuit of the capacitors at three levels. An operation control circuit controls a generation of a PWM signal to be applied to the four switching elements, to minimize a difference between a current value detected by the current detector and a target current value.