Abstract: A DC capacitor and a leg are connected in parallel to a high-voltage-side power line and a low-voltage-side power line. The leg includes a plurality of semiconductor switching elements connected in series between the power lines with an output end, connected to a load, between the plurality of semiconductor switching elements. An attenuator for attenuating a resonance is connected to a main circuit loop formed of the DC capacitor, the high-voltage-side power line, the low-voltage-side power line, a semiconductor switching element in ON state, and a drain-source parasitic capacitance of a semiconductor switching element in OFF state.

Abstract: Provided is a power conversion device that can suppress interference between control of input current from an AC power supply and voltage control for a DC capacitor to perform both the controls with high accuracy, and can reduce the capacitance and size of the DC capacitor. A power conversion circuit includes a rectification bridge circuit, a leg circuit having upper and lower legs connected in series, a DC capacitor, a smoothing capacitor, and a reactor. A control circuit performs PWM control of the leg circuit by generating a duty cycle so as to control a voltage of the DC capacitor while controlling an input current from an AC power supply, in a control cycle. When the duty cycle is generated, a sum of duty cycles is made constant in one cycle for each leg.

Abstract: An output terminal of a contact type charger connected to an AC power supply 1 and being for boosting or stepping down an input voltage, and an output terminal of a non-contact type charger for receiving power in a non-contact manner are connected to an input terminal of a DC/DC converter via an integrated bus, a DC link capacitor is connected between an AC/DC converter and an isolated DC/DC converter included in the contact type charger, an integrated capacitor is connected to the integrated bus, and a control circuit adjusts a DC voltage of the DC link capacitor or the integrated capacitor such that at least one of power losses or a total power loss of the contact type charger, the non-contact type charger, and the DC/DC converter is reduced.

Abstract: A control circuit performs at least pulse width modulation control on a first leg and selects to perform pulse width modulation control and pulse frequency modulation control, to perform pulse width modulation control and phase shift modulation control, or to perform pulse width modulation control, pulse frequency modulation control, and phase shift modulation control on a second leg, based on comparison of a voltage conversion ratio between DC voltage of a DC capacitor and output voltage to a load with at least one threshold.

Abstract: A DC capacitor and a leg are connected in parallel to a high-voltage-side power line and a low-voltage-side power line. The leg includes a plurality of semiconductor switching elements connected in series between the power lines with an output end, connected to a load, between the plurality of semiconductor switching elements. An attenuator for attenuating a resonance is connected to a main circuit loop formed of the DC capacitor, the high-voltage-side power line, the low-voltage-side power line, a semiconductor switching element in ON state, and a drain-source parasitic capacitance of a semiconductor switching element in OFF state.

Abstract: A power conversion device including: a reactor formed such that a DC winding and a plurality of coupled windings are wound around one magnetic body, one end of the DC winding is connected to a voltage source, one end of each of the plurality of coupled windings is connected to another end of the DC winding, another end of each of the plurality of coupled windings is connected to each intermediate connection point between a plurality of upper and lower arms composed of switching elements, and magnetic fluxes generated by currents flowing through the DC winding and the coupled windings merge with each other in the same direction; and a control device for controlling the switching elements, wherein the upper arms or the lower arms are controlled by in-phase driving or interleave driving on the basis of the duty of switching operation.

Abstract: A control circuit performs at least pulse width modulation control on a first leg and selects to perform pulse width modulation control and pulse frequency modulation control, to perform pulse width modulation control and phase shift modulation control, or to perform pulse width modulation control, pulse frequency modulation control, and phase shift modulation control on a second leg based on comparison of a voltage conversion ratio between DC voltage of a DC capacitor and output voltage to a load with at least one threshold.

Abstract: A power conversion device includes: a main body including a substrate to which a power conversion unit and a coil are provided; and a first heat dissipation portion which holds the substrate and dissipates heat of the substrate, wherein the substrate is formed by one sheet, the coil is formed integrally with the substrate, the first heat dissipation portion is fixed to a substrate first surface of the substrate, a heat dissipation second surface of the first heat dissipation portion has a coil cooling portion opposed to and abutting on a part where the coil is formed, of the substrate.

Abstract: A period from when switching elements S1, S4 at first diagonal positions in a full-bridge inverter are turned off at the same time to when switching elements S2, S3 at second diagonal positions are turned on at the same time, is defined as T1, and a period from when the switching elements S2, S3 at the second diagonal positions are turned off at the same time to when the switching elements S1, S4 at the first diagonal positions are turned on at the same time, is defined as T2. With a total length of T1 and T2 set to be constant, the lengths of T1 and T2 are controlled to be changed every switching cycle.

Abstract: A power conversion device includes an input detector for detecting input parameters of the DC input to the inverter; an output detector for detecting output parameters of the DC output from the power converter device; a duty calculator for calculating a duty for the switching elements of the inverter; a frequency search range calculator for determining an upper limit and a lower limit of a frequency search range for determining the drive frequency after the operating condition is changed, using at least one parameter of the input parameters, the output parameters, and a duty parameter; and a frequency search processor for determining the drive frequency by searching the frequency search range.

Abstract: A full-bridge inverter is configured with a parallel connection of a first leg and a second leg, and controlled in a dual-leg resonant mode in which a positive-side switching element of the first leg and a negative-side switching element of the second leg are turned on/off at the same time and a negative-side switching element of the first leg and a positive-side switching element of the second leg are turned on/off at the same time, and controlled in a single-leg resonant mode in which the positive-side switching element of the first leg and the negative-side switching element of the second leg, and the negative-side switching element of the first leg and the positive-side switching element of the second leg are turned on/off shiftedly in time by a phase shift amount.

Abstract: A power conversion device including: a reactor formed such that a DC winding and a plurality of coupled windings are wound around one magnetic body, one end of the DC winding is connected to a voltage source, one end of each of the plurality of coupled windings is connected to another end of the DC winding, another end of each of the plurality of coupled windings is connected to each intermediate connection point between a plurality of upper and lower arms composed of switching elements, and magnetic fluxes generated by currents flowing through the DC winding and the coupled windings merge with each other in the same direction; and a control device for controlling the switching elements, wherein the upper arms or the lower arms are controlled by in-phase driving or interleave driving on the basis of the duty of switching operation.

Abstract: A power conversion device includes an input detector for detecting input parameters of the DC input to the inverter; an output detector for detecting output parameters of the DC output from the power converter device; a duty calculator for calculating a duty for the switching elements of the inverter; a frequency search range calculator for determining an upper limit and a lower limit of a frequency search range for determining the drive frequency after the operating condition is changed, using at least one parameter of the input parameters, the output parameters, and a duty parameter; and a frequency search processor for determining the drive frequency by searching the frequency search range.

Abstract: This power conversion device includes: a rectification circuit; an inverter circuit having a full-bridge configuration, and having a DC capacitor, and first and second legs each of which has two switching elements connected in series to each other; a transformer; and a control circuit for controlling operation of the inverter circuit, wherein the control circuit controls an ON period for the first leg, thereby controlling increase/decrease in current flowing through a first rectification circuit from an AC input, and controls an ON period for the second leg and a phase shift amount between the ON period for the first leg and the ON period for the second leg, thereby controlling voltage of the DC capacitor to be constant. Thus, it becomes possible to achieve high-power-factor control and output power control at the same time by a single stage of full-bridge inverter circuit.

Abstract: A full-bridge inverter is configured with a parallel connection of a first leg and a second leg, and controlled in a dual-leg resonant mode in which a positive-side switching element of the first leg and a negative-side switching element of the second leg are turned on/off at the same time and a negative-side switching element of the first leg and a positive-side switching element of the second leg are turned on/off at the same time, and controlled in a single-leg resonant mode in which the positive-side switching element of the first leg and the negative-side switching element of the second leg, and the negative-side switching element of the first leg and the positive-side switching element of the second leg are turned on/off shiftedly in time by a phase shift amount.

Abstract: A transformer is composed of three or more windings magnetically coupled. An AC/DC converter (2) for converting AC power of an AC power supply (1), a capacitor (3), and a switching circuit (4) are connected to one winding (6a), and a switching circuit (8) or (30) for power conversion of a DC power supply is connected to at least one of the other windings. Voltage of the capacitor (3) or the AC power supply (1) is detected. On the basis of the detected value thereof, the operation state of each switching circuit (4), (8), (30) is determined by an operation state determination circuit (101). On the basis of a result of the determination, the power supply is switched among the AC power supply (1) and the DC power supplies (11) and (34) by an output switch circuit (103).

Abstract: A power conversion device includes a reactor, a single-phase inverter, and a single-phase converter which are connected in series to each other between an AC power supply and a smoothing capacitor, and performs power conversion between AC voltage of the AC power supply and DC voltage of the smoothing capacitor. The power conversion device includes a control unit which controls switch elements of the single-phase inverter and switch elements of the single-phase converter so that charging operation and discharging operation of the DC capacitor are performed in one switching cycle of the single-phase inverter and the charging amount and the discharging amount thereof are equal to each other.

Abstract: A first winding, a second winding, a fourth winding, and a fifth winding functioning as a transformer are wound around respective side legs of a three-leg core. Third windings functioning as a DC reactor are wound around a center leg. Winding directions of the first winding, the second winding, and the third windings are set so that magnetic fluxes generated by DC currents flowing through the respective windings merge in the same direction at the center leg, and winding directions of the fourth winding and the fifth winding are set so that magnetic fluxes generated by AC currents flowing through the respective windings cancel each other at the center leg. Thus, the transformer and the DC reactor are integrated using the three-leg core, whereby size reduction and loss reduction of the integrated magnetic component are achieved.

Abstract: A power conversion device includes a reactor, a single-phase inverter, and a single-phase converter which are connected in series to each other between an AC power supply and a smoothing capacitor, and performs power conversion between AC voltage of the AC power supply and DC voltage of the smoothing capacitor. The power conversion device includes a control unit which controls switch elements of the single-phase inverter and switch elements of the single-phase converter so that charging operation and discharging operation of the DC capacitor are performed in one switching cycle of the single-phase inverter and the charging amount and the discharging amount thereof are equal to each other.

Abstract: An electric power conversion device which performs conversion to desired voltage using charge and discharge of a DC capacitor includes: a reactor connected to a rectification circuit; a leg part in which diodes and first and second switching elements are connected in series between positive and negative terminals of a smoothing capacitor, and to which the reactor is connected; and the DC capacitor. A control circuit performs high-frequency PWM control for the first and second switching elements using the same drive cycle, with their reference phases shifted from each other by a half cycle, and controls a sum and a ratio of ON periods of the first and second switching elements in one cycle, thereby allowing both high-power-factor control for input AC current and voltage control for the DC capacitor.