A power conversion device includes a power conversion circuit and a power conversion control circuit. The power conversion control circuit is configured to calculate a positive-phase sequence current command signal based on a positive-phase sequence voltage of the three-phase AC output voltage and a positive-phase sequence current of the three-phase AC output current, calculate a negative-phase sequence current command signal based on the first axis negative-phase sequence current command value, the second axis negative-phase sequence current command value, the first axis negative-phase sequence current value, and the second axis negative-phase sequence current value, and generate the switching control signal based on the positive-phase sequence current command signal and the negative-phase sequence current command signal.

A power conversion device includes a power conversion circuit and a power conversion control circuit. The power conversion control circuit is configured to calculate a positive-phase sequence current command signal based on a positive-phase sequence voltage of the three-phase AC output voltage and a positive-phase sequence current of the three-phase AC output current, calculate a negative-phase sequence current command signal based on the first axis negative-phase sequence current command value, the second axis negative-phase sequence current command value, the first axis negative-phase sequence current value, and the second axis negative-phase sequence current value, and generate the switching control signal based on the positive-phase sequence current command signal and the negative-phase sequence current command signal.

A power conversion device of an embodiment includes a power conversion unit, a first capacitor, a gate circuit, a bypass circuit, and a discharging circuit. The power conversion unit includes a plurality of switching elements each having a gate and generates alternating current (AC) power from direct current (DC) power supplied to a provided DC input terminal. The first capacitor is provided on a DC input side of the power conversion unit. The gate circuit includes a drive circuit configured to output a gate drive signal to be supplied to gates of one or more switching elements among the plurality of switching elements and a second capacitor configured to smooth a power supply voltage of power to be supplied to the drive circuit. The bypass circuit causes the second capacitor to be charged with a part of power stored in the first capacitor at the time of power supply loss of a control system circuit and enables the gate drive signal to be maintained in a negative bias by power stored in the second capacitor.

A power conversion device of an embodiment includes a power conversion unit, a first capacitor, a gate circuit, a bypass circuit, and a discharging circuit. The power conversion unit includes a plurality of switching elements each having a gate and generates alternating current (AC) power from direct current (DC) power supplied to a provided DC input terminal. The first capacitor is provided on a DC input side of the power conversion unit. The gate circuit includes a drive circuit configured to output a gate drive signal to be supplied to gates of one or more switching elements among the plurality of switching elements and a second capacitor configured to smooth a power supply voltage of power to be supplied to the drive circuit. The bypass circuit causes the second capacitor to be charged with a part of power stored in the first capacitor at the time of power supply loss of a control system circuit and enables the gate drive signal to be maintained in a negative bias by power stored in the second capacitor.

A power conversion device of an embodiment includes a power conversion unit, a first capacitor, a gate circuit, a bypass circuit, and a discharging circuit. The power conversion unit includes a plurality of switching elements each having a gate and generates alternating current (AC) power from direct current (DC) power supplied to a provided DC input terminal. The first capacitor is provided on a DC input side of the power conversion unit. The gate circuit includes a drive circuit configured to output a gate drive signal to be supplied to gates of one or more switching elements among the plurality of switching elements and a second capacitor configured to smooth a power supply voltage of power to be supplied to the drive circuit. The bypass circuit causes the second capacitor to be charged with a part of power stored in the first capacitor at the time of power supply loss of a control system circuit and enables the gate drive signal to be maintained in a negative bias by power stored in the second capacitor.

A vehicle operates an internal combustion engine according to an automatic start-stop function to reduce fuel consumption. A first DC bus is adapted to connect to a plurality of DC loads. A primary battery is coupled between the first DC bus and a ground. A first alternator is driven by the internal combustion engine to supply electrical power to the first DC bus. A second DC bus is connected to a positive terminal of an auxiliary battery. A negative terminal of the auxiliary battery is connected to the first DC bus. A second alternator is driven by the internal combustion engine to supply electrical power to the second bus at a voltage corresponding to a sum of voltages of the primary and auxiliary batteries. An inverter receives electrical power from the second DC bus to generate an AC output adapted to connect to accessory AC loads.

A vehicle operates an internal combustion engine according to an automatic start-stop function to reduce fuel consumption. A first DC bus is adapted to connect to a plurality of DC loads. A primary battery is coupled between the first DC bus and a ground. A first alternator is driven by the internal combustion engine to supply electrical power to the first DC bus. A second DC bus is connected to a positive terminal of an auxiliary battery. A negative terminal of the auxiliary battery is connected to the first DC bus. A second alternator is driven by the internal combustion engine to supply electrical power to the second bus at a voltage corresponding to a sum of voltages of the primary and auxiliary batteries. An inverter receives electrical power from the second DC bus to generate an AC output adapted to connect to accessory AC loads.

A power device includes a semiconductor relay and a pre-charger that has a reference voltage generator and a controller. The semiconductor relay is disposed at a position between a battery supplying electric power to a power converter that serves as a load and a smoothing capacitor connected on a battery side of the power converter in parallel with the power converter. The reference voltage generator generates a reference voltage having a gradually-increasing voltage value in a pre-charge period, prior to a turning ON of the semiconductor relay accompanying a turning ON of an ignition switch. The controller controls the semiconductor relay such that a charge voltage which is an inter-terminal voltage of the smoothing capacitor is set to a preset value according to the reference voltage.

A power device includes a semiconductor relay and a pre-charger that has a reference voltage generator and a controller. The semiconductor relay is disposed at a position between a battery supplying electric power to a power converter that serves as a load and a smoothing capacitor connected on a battery side of the power converter in parallel with the power converter. The reference voltage generator generates a reference voltage having a gradually-increasing voltage value in a pre-charge period, prior to a turning ON of the semiconductor relay accompanying a turning ON of an ignition switch. The controller controls the semiconductor relay such that a charge voltage which is an inter-terminal voltage of the smoothing capacitor is set to a preset value according to the reference voltage.

A solar pump system comprises a solar module configured to generate DC power from sunlight, a water pump, an inverter configured to convert the DC power into AC power in order to drive the water pump, and a controller configured to generate a control signal for controlling an output frequency of the AC power. The controller compares the DC link voltage with a first reference level, adjusts the output frequency of the AC power, if the DC link voltage is greater than the first reference level, and determines the output frequency to prevent the DC link voltage from being equal to or less than a second reference level, if the DC link voltage is less than the first reference level.