Abstract: A power conversion apparatus is equipped with switching devices to perform power conversion of input AC power supplied from an AC power supply to output AC power having a predetermined voltage and a predetermined frequency, and to supply the power to a motor connected thereto. The apparatus includes a controller controlling switching of the switching devices, a capacitor smoothing a ripple generated by the switching of the switching devices, a current controller controlling a current flowing to the motor, and a voltage distortion corrector detecting a harmonic component caused by distortion in motor input power, and superimposing compensation values on an output of the current controller in accordance with a value of the harmonic component.

Abstract: A DC link is provided, which includes a capacitor connected in parallel to an output of a converter circuit, and outputs a pulsating DC link voltage. An inverter circuit is provided, which converts an output of the DC link to AC by switching, and supplies the AC to a motor connected thereto. A controller is provided, which controls switching of the inverter circuit so that motor currents pulsate in synchronization with pulsation of a power-supply voltage. The controller controls the switching of the inverter circuit in accordance with a load of the motor or an operational state of the motor, and reduces pulsation amplitude of the motor currents.

Abstract: A multiphase current supplying circuit according to the present invention includes a diode bridge, an intervening circuit, an inverter, a control circuit, and a lightning arrester. The diode bridge is connected to a single-phase AC power supply system via the lightning arrester, and performs full-wave rectification on a single-phase AC voltage. The intervening circuit includes a capacitor and an inductor, and is constituted by a choke input type low-pass filter. More specifically, one end of the inductor and one end of the capacitor are connected, output from the diode bridge is received between the other end of the inductor and the other end of the capacitor, and a rectified voltage generated at both ends of the capacitor is output to the inverter.

Abstract: The power converter includes a diode rectifier which rectifies alternating current power output from an alternating current power supply, a reactor provided between the alternating current power supply and the diode rectifier, an inverter circuit to which power output from the diode rectifier is directly supplied, and a capacitor provided between power supply lines on a primary side of the diode rectifier.

Abstract: A power converter includes a power converter section (4) (e.g., an inverter circuit) having a plurality of switching elements (Sp, Sn) in which a current can flow in a reverse direction, and a control section (10) which determines on-state time of each of the switching elements (Sp, Sn) according to an output voltage of the power converter section (4), thereby switching on/off states of the switching elements (Sp, Sn). The control section (10) instructs the power converter section (4) to perform synchronous rectification, and corrects the on-state time according to a drop of an on-state voltage of each of the switching elements (Sp, Sn).

Abstract: A power converter circuit includes a diode group, a relay, a DC section and an inverter. The diode group includes a plurality of diodes arranged to rectify an output voltage of an alternating-current power supply. The relay is provided at a point located closer to the alternating-current power supply than the diode group. The DC section is where an output voltage of the diode group is applied. The inverter is arranged to output a three-phase alternating-electric current to a three-phase load. The DC section has a maximum pulse voltage twice as great as a minimum pulse voltage of the DC section. The DC section includes an energy-absorbing circuit having an electrolytic capacitor. The DC section further has a pathway arranged to apply the output voltage of the alternating-current power supply from the alternating-current power supply to the electrolytic capacitor via a rectifying circuit, not via the relay.

Abstract: A motor control unit (10) includes: a power converter (40) having a rectifier circuit (20) which rectifies an AC voltage from an AC power supply (31), a capacitor circuit (22) which receives an output of the rectifier circuit (20) and outputs a rectified voltage having pulses from both ends of a capacitor (13) and an inverter circuit (25) which receives the rectified voltage and outputs an AC voltage to the motor (30); and a motor controller (41) controlling the motor (30) by controlling the inverter circuit (25). The motor controller (41) performs torque control to vary an output toque of the motor (30) in response to variation in load torque of the motor (30).

Abstract: In the case where a chip is made of wide band gap semiconductor, a power conversion apparatus is obtained in which a component having a low heat resistant temperature is prevented from receiving thermal damage by heat generated at the chip. In a configuration including: a chip portion (20) including a chip (21) made of wide band gap semiconductor and a member (22, 23) having a heat resistant temperature equal to or higher than that of the chip (21); and a peripheral component (25) arranged in the vicinity of the chip portion (20) and having a heat resistant temperature lower than that of the chip (21). The chip (21) and the peripheral component (25) are thermally insulated from each other so that the temperature of the peripheral component (25) does not exceed the heat resistant temperature of the peripheral component (25).

Abstract: A bidirectional switch circuit includes two switching elements connected to conduct a current in both directions. The two switching elements are connected in series to each other. Of the two switching elements, the switching element to which a reverse voltage is applied, a voltage of a source of one of the switching elements being higher than a voltage of a drain of the one, is configured to conduct a current from the source to the drain even when an on-drive signal is not being input to a gate terminal of the one.

Abstract: In a power converter for converting AC power supplied from an AC power source or DC power supplied from a DC power source to DC power or AC power having predetermined voltage and frequency including at least one switching device (130) configured to be operable at high temperature, at least one snubber circuit (300) configured to be operable at high temperature and having a capacitor (301) configured to be operable at high temperature is provided.

Abstract: An inverter circuit (120) is configured so as to perform synchronous rectification by six switching elements (130). The switching element (130) is formed of an unipolar device (SiC MOSFET in this case) using a wideband gap semiconductor. The inverter circuit (120) uses the body diode (131) of SiC MOSFET (130) as a freewheeling diode during synchronous rectification.

Abstract: A multiphase current supplying circuit includes a converter, an intervening circuit, an inverter, a control circuit and a lightning arrester. A power supply system is connected to the converter with the lightning arrester interposed therebetween, and the ac voltage is rectified. The intervening circuit includes a capacitor and a bypass connected in parallel thereto. In the bypass, a diode, a resistor and a capacitor are connected in series, and the direction from an anode to a cathode of the diode corresponds to the direction from a high potential side to a low potential side of the smoothing capacitor.

Abstract: This invention is to reduce a voltage across a smoothing capacitor in a single-phase capacitorless inverter. A smoothing circuit (15) has a smoothing capacitor (C) connected between a pair of power supply lines (L1, L2). A diode (Ds) has its anode connected to one of the power supply lines (L1) and has its cathode connected to an end of a resistor (Rs), the other end of the resistor is connected to an end of a capacitor (Cs), the other end of the capacitor is connected to the other of the power supply lines (L2). In this way, the magnitude of a rectified voltage (Vdc) across the smoothing capacitor (C) can be reduced as compared with an absence of the series connection of diode (Ds), resistor (Rs) and capacitor (Cs).

Abstract: In the case where a chip is made of wide band gap semiconductor, a power conversion apparatus is obtained in which a component having a low heat resistant temperature is prevented from receiving thermal damage by heat generated at the chip. In a configuration including: a chip portion (20) including a chip (21) made of wide band gap semiconductor and a member (22, 23) having a heat resistant temperature equal to or higher than that of the chip (21); and a peripheral component (25) arranged in the vicinity of the chip portion (20) and having a heat resistant temperature lower than that of the chip (21). The chip (21) and the peripheral component (25) are thermally insulated from each other so that the temperature of the peripheral component (25) does not exceed the heat resistant temperature of the peripheral component (25).

Abstract: A motor control unit (10) includes: a power converter (40) having a rectifier circuit (20) which rectifies an AC voltage from an AC power supply (31), a capacitor circuit (22) which receives an output of the rectifier circuit (20) and outputs a rectified voltage having pulses from both ends of a capacitor (13) and an inverter circuit (25) which receives the rectified voltage and outputs an AC voltage to the motor (30); and a motor controller (41) controlling the motor (30) by controlling the inverter circuit (25). The motor controller (41) performs torque control to vary an output toque of the motor (30) in response to variation in load torque of the motor (30).

Abstract: A multiphase current supplying circuit includes a converter, an intervening circuit, an inverter, a control circuit and a lightning arrester. A power supply system is connected to the converter with the lightning arrester interposed therebetween, and the ac voltage is rectified. The intervening circuit includes a capacitor and a bypass connected in parallel thereto. In the bypass, a diode, a resister and a capacitor are connected in series, and the direction from an anode to a cathode of the diode corresponds to the direction from a high potential side to a low potential side of the smoothing capacitor.

Abstract: A multiphase current supplying circuit according to the present invention includes a diode bridge, an intervening circuit, an inverter, a control circuit, and a lightning arrester. The diode bridge is connected to a single-phase AC power supply system via the lightning arrester, and performs full-wave rectification on a single-phase AC voltage. The intervening circuit includes a capacitor and an inductor, and is constituted by a choke input type low-pass filter. More specifically, one end of the inductor and one end of the capacitor are connected, output from the diode bridge is received between the other end of the inductor and the other end of the capacitor, and a rectified voltage generated at both ends of the capacitor is output to the inverter.

Abstract: This invention is to reduce a voltage across a smoothing capacitor in a single-phase capacitorless inverter. A smoothing circuit (15) has a smoothing capacitor (C) connected between a pair of power supply lines (L1, L2). A diode (Ds) has its anode connected to one of the power supply lines (L1) and has its cathode connected to an end of a resistor (Rs), the other end of the resistor is connected to an end of a capacitor (Cs), the other end of the capacitor is connected to the other of the power supply lines (L2). In this way, the magnitude of a rectified voltage (Vdc) across the smoothing capacitor (C) can be reduced as compared with an absence of the series connection of diode (Ds), resistor (Rs) and capacitor (Cs).