Abstract: A power conversion apparatus includes a converter circuit converting AC voltage output from an AC power supply into DC voltage. The converter circuit includes unit converters. The power conversion apparatus includes a low current-oriented controller the unit converters to cause current corresponding to a single phase to flow through a current detector, and a high current-oriented controller controlling operation of the unit converters based on a result of comparison between a duty command and a carrier signal, where the duty command is generated based on detection values detected by the current detector and a voltage detector. When the detection value detected by the current detector is less than or equal to a first threshold, the low current-oriented controller is activated, and when the detection value detected by the current detector is greater than the first threshold, the high current-oriented controller is activated.

Abstract: An outdoor unit includes a housing, a heat exchanger, an electric component box, a substrate, and a heat dissipator including multiple fins. The fins each have a first end situated in a windward side of an air passage formed between adjacent ones of the fins, and the first end faces the electric component box. When the heat dissipator and the electric component box are viewed from above, a first clearance gap having a first width and a second clearance gap having a second width greater than the first width are formed between the first end and the electric component box. The second clearance gap is situated closer to a back panel than the first clearance gap.

Abstract: A power conversion apparatus includes a converter circuit converting alternating current voltage output from an AC power supply into direct current voltage. The converter circuit includes unit converters. The power conversion apparatus generates a reference duty based on detection values of a current detector and a voltage detector, and generates a pulse width modulation signal based on a result of comparison between a carrier signal and a corrected duty obtained by correcting the reference duty. When a first reference duty in a first carrier period differs from a second reference duty in a second carrier period subsequent to the first carrier period, a first corrected duty of a first phase in a first carrier period in one power supply period after and a second corrected duty of a second phase in the first carrier period in one power supply period after are controlled to have different values.

Abstract: A power conversion apparatus includes a converter circuit and a control unit. The converter circuit includes circuits for the number of phases being more than one, the circuits each including a reactor and a corresponding first or second switching element connected to the reactor. The converter circuit converts an AC voltage output from a commercial power supply into a DC voltage. In a case where a time difference between a timing of turning off the first switching element and a timing of turning on the second switching element is within a threshold, the control unit performs control for advancing or delaying the timing of turning off the first switching element.

Abstract: A direct-current power supply includes: a plurality of semiconductor devices each of which is a multiphase converter incorporating a plurality of semiconductor switching elements and a drive circuit to drive the plurality of semiconductor switching elements; a plurality of first parasitic inductances, each of which connects a reference potential terminal of the drive circuit and output N terminals of the semiconductor switching elements, in the plurality of semiconductor devices; a smoothing capacitor; and an inverter.

Abstract: A motor drive device includes a reactor, a converter circuit, a capacitor, an inverter circuit, and overcurrent determination units. The converter circuit converts a first AC voltage output from an AC power supply into a DC voltage. The capacitor smooths a second voltage on the DC side of the converter circuit. The inverter circuit converts DC power stored in the capacitor into AC power. One of the overcurrent determination units determines overcurrent based on a detected value of the first AC current, flowing between the AC power supply and the converter circuit. Another overcurrent determination unit determines overcurrent based on a detected value of the second DC current, flowing between the converter circuit and the capacitor. The converter and inverter circuits stop operating when the determination result of one of the overcurrent determination units indicates an overcurrent.

Abstract: A power supply includes: a converter circuit including boost circuits, the converter circuit boosting a voltage output from a power source; a current detector that detects a first current flowing between the power source and the converter circuit; current detectors that each detect a second current, the second current being a sum current of currents flowing in switching elements of the boost circuits; and overcurrent determiners that determine whether the second currents are overcurrent on the basis of detection values of the second currents. When a result of the determination made by corresponding one of the overcurrent determiners indicates overcurrent, the boost circuits stop operating.

Abstract: A converter device includes: a power conversion circuit including a reactor and a switching element, rectifying a voltage of alternating-current power supplied from an alternating-current power supply to a direct-current voltage, and boosting and outputting the direct-current voltage; a current detector detecting a current flowing in the reactor; a filter circuit filtering a first signal detected by the current detector; and a control unit generating a control signal on the basis of a carrier and a second signal generated by the filter circuit and controlling, on the basis of the control signal and with a first period, the switching element, the first period being a period of the carrier. The filter circuit cuts off a repetition frequency component in the first period and passes a repetition frequency component in a second period, the second period being longer than the first period.

Abstract: A direct-current power supply apparatus includes: a reactor having one end connected to an alternating-current power supply; a bridge circuit, connected to an opposite end of the reactor, converting an alternating-current first voltage output from the alternating-current power supply into a direct-current voltage; and a current detector detecting an alternating current flowing between the alternating-current power supply and the bridge circuit. The reactor reduces an inductance in accordance with an increase of the alternating current and, when the alternating current exceeds a first current, has an inductance lower than one third of an inductance at which a current does not flow in the reactor. The bridge circuit performs an active operation when the detection value of the alternating current is larger than or equal to the first current and performs a passive operation when the detection value of the alternating current is lower than the first current.

Abstract: A power converting apparatus includes: a reactor that includes a first terminal and a second terminal, the first terminal being connected to an alternating-current power supply; a bridge circuit that is connected to the second terminal of the reactor, includes at least one or more switching elements, and converts an alternating-current voltage output from the alternating-current power supply into a direct-current voltage; a power-supply current detecting unit that detects a current from the alternating-current power supply; and a control unit that controls ON and OFF of the switching elements depending on a current value detected by the power-supply current detecting unit, in which two or more current thresholds for controlling ON and OFF of the switching elements are included.

Abstract: A power converting apparatus includes: a bridge circuit that includes at least two legs each including switching elements connected in series, and converts an alternating-current voltage output from an alternating-current power supply into a direct-current voltage; a power-supply current detecting unit that detects a current from the alternating-current power supply; a zero crossing detecting unit that detects a voltage polarity of the alternating-current power supply; and a control unit that controls ON and OFF of the switching elements depending on outputs of the power-supply current detecting unit and the zero crossing detecting unit, in which a dead time that is set for switching and includes a change in the voltage polarity of the alternating-current power supply is longer than a dead time that is set for switching and does not include a change in the polarity.

Abstract: A noise propagating to outside of a power conversion device is reduced. A power conversion device includes at least one external electrode, a switching element, a noise filter connected between at least one external electrode and switching element, at least one first wire to connect at least one external electrode and noise filter, a second wire to connect noise filter and switching element, and a magnetic filter attached to second wire. An attenuation characteristic A [dB] and an attenuation characteristic B [dB] satisfy a relationship of B<A, where A is an attenuation characteristic of noise filter, and B is an attenuation characteristic due to spatial coupling between at least one first wire and second wire that is located between switching element and magnetic filter.

Abstract: An outdoor unit includes a housing that includes a front panel and a back panel facing the front panel. The outdoor unit further includes a bell mouth provided on the front panel and a heat dissipator that dissipates heat generated by electric components. A windward end surface and a leeward end surface of the heat dissipator are, when viewed from above, placed in a region between a virtual surface and the back panel, the virtual surface being a virtual surface that is in contact with an end of the bell mouth on a side of the back panel and is parallel to an inner surface of the front panel.

Abstract: The power conversion apparatus includes a converter circuit that converts an alternating-current voltage output from an alternating-current power supply into a direct-current voltage. The converter circuit includes unit converters. The power conversion apparatus includes current detectors that detect respective currents flowing through respective reactors. In first and second unit converters adjacent to each other among the unit converters, a phase difference between a first phase and a second phase is changed from a reference phase difference when a total current of currents detected by the respective current detectors is greater than a threshold. The first phase is a phase at a time when the switching element of the first unit converter is turned on. The second phase is a phase at a time when the switching element of the second unit converter is turned on.

Abstract: A power converting apparatus includes a converter circuit converting an alternating-current voltage output from an alternating-current power supply into a direct-current voltage. The converter circuit includes unit converters. The power converting apparatus generates a reference duty on the basis of detection values of a current detector and a voltage detector and generates, on the basis of a result of comparison between the reference duty and a carrier signal, a pulse-width modulation signal for controlling the switching element. In each of the unit converters, the pulse-width modulation signal has one pulse within a carrier period and has pulses for the number of phases within a leveling period, the leveling period being obtained by multiplying the carrier period by the number of phases. The pulses for the number of phases within the leveling period have phases all different from each other in the respective carrier periods.

Abstract: A power converter for converting a voltage of direct-current power output from a direct-current power supply, the power converter including: a printed circuit board; a reactor being configured with a conductor pattern of the printed circuit board; a semiconductor element that is connected to another end of the reactor and performs switching for storing electrical energy in the reactor so as to boost the voltage of the direct-current power from a first voltage to a second voltage; a capacitor that smooths the direct-current power boosted to the second voltage; a diode that is connected to the another end of the reactor and supplies the direct-current power boosted to the second voltage to the capacitor; and a cooler, wherein the reactor, the semiconductor element, and the diode are included in a module in a single package, and the module is cooled by the cooler.

Abstract: The power conversion apparatus includes a converter circuit that converts an alternating-current voltage output from an alternating-current power supply into a direct-current voltage. The converter circuit includes unit converters. The power conversion apparatus includes current detectors that detect respective currents flowing through respective reactors. In first and second unit converters adjacent to each other among the unit converters, a phase difference between a first phase and a second phase is changed from a reference phase difference when a total current of currents detected by the respective current detectors is greater than a threshold. The first phase is a phase at a time when the switching element of the first unit converter is turned on. The second phase is a phase at a time when the switching element of the second unit converter is turned on.

Abstract: A power conversion apparatus includes a converter circuit converting AC voltage output from an AC power supply into DC voltage. The converter circuit includes unit converters. The power conversion apparatus includes a low current-oriented controller the unit converters to cause current corresponding to a single phase to flow through a current detector, and a high current-oriented controller controlling operation of the unit converters based on a result of comparison between a duty command and a carrier signal, where the duty command is generated based on detection values detected by the current detector and a voltage detector. When the detection value detected by the current detector is less than or equal to a first threshold, the low current-oriented controller is activated, and when the detection value detected by the current detector is greater than the first threshold, the high current-oriented controller is activated.

Abstract: A power conversion apparatus includes a converter circuit converting alternating current voltage output from an AC power supply into direct current voltage. The converter circuit includes unit converters. The power conversion apparatus generates a reference duty based on detection values of a current detector and a voltage detector, and generates a pulse width modulation signal based on a result of comparison between a carrier signal and a corrected duty obtained by correcting the reference duty. When a first reference duty in a first carrier period differs from a second reference duty in a second carrier period subsequent to the first carrier period, a first corrected duty of a first phase in a first carrier period in one power supply period after and a second corrected duty of a second phase in the first carrier period in one power supply period after are controlled to have different values.

Abstract: A power converter is connected between a power supply source of a first direct current power and a power supply destination of a second direct current power obtained by performing power conversion on the first direct current power. The power converter includes: a switching element; a reactor; a first diode; a first capacitor; a second diode. The reactor is connected to a first end of the switching element. The first end of the switching element and a first end of the reactor are connected to a first connection point. A cathode of the first diode is connected to a second end of the reactor. The cathode of the first diode and the second end of the reactor are connected to a second connection point. The second diode includes an anode connected to the first connection point and a cathode connected to the power supply destination.