Abstract: A power conversion apparatus includes a power converter, a target command controller, a feedback controller, and a gain adjustor. The power converter is configured to convert first power supplied from a power generation source into second power. The target command controller is configured to increase or decrease a target command so as to cause the first power to follow maximum suppliable power of the power generation source. The feedback controller is configured to control the power converter by feedback control that is based on a deviation between the target command and at least one of a supplied voltage and a supplied current supplied from the power generation source to the power converter. The gain adjustor is configured to adjust a gain of the feedback control based on at least one of the supplied voltage, the supplied current, and the target command.

Abstract: A power converting device includes power conversion circuitry connected to a power system, voltage amplitude determination circuitry that determines a voltage amplitude of the power system, and control circuitry that controls an output current from the power conversion circuitry to the power system based on an oscillation component of the voltage amplitude determined by the voltage amplitude determination circuitry.

Abstract: A power conversion device includes a switching circuit and a switch driver. The switching circuit includes a plurality of switching elements including a first switching element and a second switching element that are electrically coupled in series. The switch driver includes a first, a second, and a third switching pattern controller. The first switching pattern controller executes a first switching pattern which is set such that a current in a reverse direction flows through the first switching element and the second switching element is off. The second switching pattern controller executes a second switching pattern which is set such that a direction of the current flowing through the first switching element is switched to a forward direction from the reverse direction. The third switching pattern controller executes a third switching pattern which is set such that the first switching element is off and the second switching element is on.

Abstract: A power converting device includes power conversion circuitry connected to a power system, voltage amplitude determination circuitry that determines a voltage amplitude of the power system, and control circuitry that controls an output current from the power conversion circuitry to the power system based on an oscillation component of the voltage amplitude determined by the voltage amplitude determination circuitry.

Abstract: An electric power converter according to an embodiment includes a switching unit, a controller, and a second bidirectional switch. The switching unit includes a plurality of first bidirectional switches disposed between a DC power source and an AC load or between a DC load and an AC power source. The controller controls the switching unit to perform power conversion between DC power and AC power. When turning off the second bidirectional switch disposed on a path between one pole of the DC power source or the DC load and the switching unit, the controller turns on the first bidirectional switch connected between the other pole of the DC power source and the AC load or between the other pole of the DC load and the AC power source.

Abstract: A power conversion device includes a switching circuit and a switch driver. The switching circuit includes a plurality of switching elements including a first switching element and a second switching element that are electrically coupled in series. The switch driver includes a first, a second, and a third switching pattern controller. The first switching pattern controller executes a first switching pattern which is set such that a current in a reverse direction flows through the first switching element and the second switching element is off. The second switching pattern controller executes a second switching pattern which is set such that a direction of the current flowing through the first switching element is switched to a forward direction from the reverse direction. The third switching pattern controller executes a third switching pattern which is set such that the first switching element is off and the second switching element is on.

Abstract: A power conversion apparatus includes a power converter, a target command controller, a feedback controller, and a gain adjustor. The power converter is configured to convert first power supplied from a power generation source into second power. The target command controller is configured to increase or decrease a target command so as to cause the first power to follow maximum suppliable power of the power generation source. The feedback controller is configured to control the power converter by feedback control that is based on a deviation between the target command and at least one of a supplied voltage and a supplied current supplied from the power generation source to the power converter. The gain adjustor is configured to adjust a gain of the feedback control based on at least one of the supplied voltage, the supplied current, and the target command.

Abstract: An electric power converter according to an embodiment includes a switching unit, a controller, and a second bidirectional switch. The switching unit includes a plurality of first bidirectional switches disposed between a DC power source and an AC load or between a DC load and an AC power source. The controller controls the switching unit to perform power conversion between DC power and AC power. When turning off the second bidirectional switch disposed on a path between one pole of the DC power source or the DC load and the switching unit, the controller turns on the first bidirectional switch connected between the other pole of the DC power source and the AC load or between the other pole of the DC load and the AC power source.

Abstract: A grid interconnection apparatus includes a voltage conversion section including DC/DC converters to step up or down output voltages of DC power sources. The voltage conversion section combines DC power outputs from the DC/DC converters into combined DC power and output the DC power. A power conversion section converts the DC power output from the voltage conversion section into AC power, and outputs the AC power to a power grid. A current detector detects a current input into the power conversion section. A voltage detector detects a voltage input into the power conversion section. A controller controls the DC/DC converters to maximize the power outputs from the DC power sources based on the detected current and the detected voltage.

Abstract: A three-level inverter includes a set of series-connected capacitors connected in parallel to a direct-current power supply; two arms connected in parallel to an output of the direct-current power supply and each having an alternating-current output terminal; and a control section having a neutral voltage controller determining a three-phase voltage correction command based on a neutral voltage and voltage of the direct-current power supply, having a coordinate converter converting the three-phase voltage correction command to a voltage correction command on d-q axis, and suppressing voltage variations at the neutral point by correcting a voltage command on d-q axis based on the d-q voltage correction command. The neutral point is connected to one grounded phase of a three-phase grounded power system. The alternating-current output terminals are connected to respective non-grounded phases of the power system. A power conditioner includes the three-level inverter.

Abstract: A three-level inverter includes a set of series-connected capacitors connected in parallel to a direct-current power supply; two arms connected in parallel to an output of the direct-current power supply and each having an alternating-current output terminal; and a control section having a neutral voltage controller determining a three-phase voltage correction command based on a neutral voltage and voltage of the direct-current power supply, having a coordinate converter converting the three-phase voltage correction command to a voltage correction command on d-q axis, and suppressing voltage variations at the neutral point by correcting a voltage command on d-q axis based on the d-q voltage correction command. The neutral point is connected to one grounded phase of a three-phase grounded power system. The alternating-current output terminals are connected to respective non-grounded phases of the power system. A power conditioner includes the three-level inverter.