Abstract: A direct current power supply device control method and control device such that output currents of each direct current power supply unit are balanced with high accuracy using droop control that reflects wiring resistance from a multiple of direct current power supply units operated in parallel to a load. A droop characteristic of each of power supply units is expressed using wiring resistance between output terminals of the power supply units, output voltage, output current, an output voltage command value, and a droop coefficient, and the wiring resistance is calculated in advance using the output voltage and output current of each unit and voltage of an output point. When the units are operated in parallel, an output voltage command value of each unit is calculated using output current of the same magnitude common to all units, the output voltage of each unit, the droop coefficient, and the wiring resistance.

Abstract: In a power conversion device, a constant voltage can be supplied even when the voltage of an alternating current power supply fluctuates. A switching element Q1 and switching element Q2 are connected to a direct current power supply series circuit. A connection point of a direct current power supply and direct current power supply is a neutral point terminal, a connection point of the switching element Q1 and switching element Q2 is an output terminal, switch elements S1 and S2 are connected between the output terminal and neutral point terminal, switch elements S3 and S4 are connected between a terminal R of an alternating current power supply having a terminal S connected to the neutral point terminal, and the output terminal, and a first element and second element selected from among the switching elements Q1 and Q2 and switch elements S1 to S4 are turned on and off complementarily.

Abstract: A method and related devices for controlling an output voltage of a direct current power supply device. An output voltage command value of a battery unit is calculated in advance by adding output voltage when a power supply unit acting as a main power supply unit operates and a voltage drop caused by wiring resistance from the battery unit, which acts as a back-up unit, to an output point, whereby, when the back-up operation is carried out, voltage of the output point when the battery unit is operated in accordance with the output voltage command value is equivalent to the voltage of the output point when the power supply unit is operated when an alternating current power supply is sound.

Abstract: A direct current power supply device control method and control device such that output currents of each direct current power supply unit are balanced with high accuracy using droop control that reflects wiring resistance from a multiple of direct current power supply units operated in parallel to a load. A droop characteristic of each of power supply units is expressed using wiring resistance between output terminals of the power supply units, output voltage, output current, an output voltage command value, and a droop coefficient, and the wiring resistance is calculated in advance using the output voltage and output current of each unit and voltage of an output point. When the units are operated in parallel, an output voltage command value of each unit is calculated using output current of the same magnitude common to all units, the output voltage of each unit, the droop coefficient, and the wiring resistance.

Abstract: A power conversion apparatus includes first, second, third, and fourth switching elements. In a first period, the second and third switching elements are switched ON, and first and fourth switching elements are alternately switched ON/OFF. In a second period, the first and fourth switching elements are switched ON, and the second and third switching elements are alternately switched ON/OFF. In a third period, the first and second switching elements are switched ON, and the third and fourth switching elements are switched OFF. The power conversion apparatus provides a release path for inductive energy accumulated in a reactor.

Abstract: A power converter includes a first arm configured by connecting a diode to a switching element, a second arm configured by connecting a diode to another switching element, a third arm formed of a first bidirectional switch configured by connecting switch elements, and a fourth arm formed of a second bidirectional switch configured by connecting other switch elements. An inverter circuit is configured by connecting the first and second arms in series between terminals of a direct current power source circuit, by connecting the third arm between a terminal of an alternating current power source and an output terminal, and by connecting the fourth arm between the output terminal and another output terminal. The control mode of the inverter circuit is switched between control modes at a timing at which at least one common arm continues a conductible condition.

Abstract: In a power conversion device, a constant voltage can be supplied even when the voltage of an alternating current power supply fluctuates. A switching element Q1 and switching element Q2 are connected to a direct current power supply series circuit. A connection point of a direct current power supply and direct current power supply is a neutral point terminal, a connection point of the switching element Q1 and switching element Q2 is an output terminal, switch elements S1 and S2 are connected between the output terminal and neutral point terminal, switch elements S3 and S4 are connected between a terminal R of an alternating current power supply having a terminal S connected to the neutral point terminal, and the output terminal, and a first element and second element selected from among the switching elements Q1 and Q2 and switch elements S1 to S4 are turned on and off complementarily.

Abstract: A power converter includes a first arm configured by connecting a diode to a switching element, a second arm configured by connecting a diode to another switching element, a third arm formed of a first bidirectional switch configured by connecting switch elements, and a fourth arm formed of a second bidirectional switch configured by connecting other switch elements. An inverter circuit is configured by connecting the first and second arms in series between terminals of a direct current power source circuit, by connecting the third arm between a terminal of an alternating current power source and an output terminal, and by connecting the fourth arm between the output terminal and another output terminal. The control mode of the inverter circuit is switched between control modes at a timing at which at least one common arm continues a conductible condition.

Abstract: An inverter circuit 40 with reduced loss in semiconductor elements when starting up, having switching elements Q1 and Q2 in series, and connected to both ends of a direct current power source circuit 30 having direct current power sources Psp and Psn in series, and including an alternating current output terminal U connected to a connection point of the switching elements, an alternating current output terminal V connected to a connection point of the direct current power sources, a bidirectional switch element S1, connected between the alternating current output terminal U and a terminal R of an alternating current power source 1, and a bidirectional switch element S2, connected between the alternating current output terminal U and a terminal S of the alternating current power source, causing the bidirectional switch elements to turn on and off when starting up.

Abstract: A power conversion apparatus includes first, second, third, and fourth switching elements. In a first period, the second and third switching elements are switched ON, and first and fourth switching elements are alternately switched ON/OFF. In a second period, the first and fourth switching elements are switched ON, and the second and third switching elements are alternately switched ON/OFF. In a third period, the first and second switching elements are switched ON, and the third and fourth switching elements are switched OFF. The power conversion apparatus provides a release path for inductive energy accumulated in a reactor.

Abstract: An inverter circuit 40 with reduced loss in semiconductor elements when starting up, having switching elements Q1 and Q2 in series, and connected to both ends of a direct current power source circuit 30 having direct current power sources Psp and Psn in series, and including an alternating current output terminal U connected to a connection point of the switching elements, an alternating current output terminal V connected to a connection point of the direct current power sources, a bidirectional switch element S1, connected between the alternating current output terminal U and a terminal R of an alternating current power source 1, and a bidirectional switch element S2, connected between the alternating current output terminal U and a terminal S of the alternating current power source, causing the bidirectional switch elements to turn on and off when starting up.