Abstract: A parallel power supply device includes a plurality of DC/DC converters connected in parallel, and each DC/DC converter includes: first and second switching circuits with a transformer therebetween; first and second reactors; and a control circuit. The control circuit generates a duty cycle so that a deviation between voltage of a load and target voltage becomes 0. Correction is performed such that, when the magnitude of the duty cycle is smaller than a set value Vth, the magnitude is fixed at 0, and otherwise, the magnitude is decreased by the set value Vth. Then, the phase shift amounts for drive signals for the first and second switching circuits are determined, and the first and second switching circuits are subjected to phase shift control.

Abstract: In this DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. A control circuit includes a first circuit for performing feedback control so as to reduce a difference between a detected value and a command value of charge current, and a second circuit for correcting one of control input and output of the first circuit on the basis of the detected value and the command value. In charging the battery, the control circuit controls a phase shift amount of a first diagonal element in the first switching circuit and a phase shift amount of a second diagonal element in the second switching circuit relative to the drive phase of a first reference element in the first switching circuit.

Abstract: In a DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. In charging the battery, a control circuit controls respectively phase shift amounts of first and second diagonal elements in the first and second switching circuits relative to the drive phase of a first reference element in the first switching circuit. During a step-up charge control period, if charge current is positive or zero, the control circuit performs control so that the phase shift amount becomes greater than the phase shift amount by an amount exceeding a short-circuit prevention time for the switching elements, allowing step-up operation to be performed, improving controllability in step-up control.

Abstract: In a DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. In charging the battery, a control circuit controls a phase shift amount of a first diagonal element in the first switching circuit and a phase shift amount of a second diagonal element in the second switching circuit relative to the drive phase of a first reference element in the first switching circuit. During a step-up charge control period, if charge current is positive or zero, the control circuit performs control so that the phase shift amount becomes greater than the phase shift amount by an amount exceeding a short-circuit prevention time for the semiconductor switching elements. Thus, step-up operation is prevented from becoming unable to be performed due to the short-circuit prevention time.

Abstract: In this DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. A control circuit includes a first circuit for performing feedback control so as to reduce a difference between a detected value and a command value of charge current, and a second circuit for correcting one of control input and output of the first circuit on the basis of the detected value and the command value. In charging the battery, the control circuit controls a phase shift amount of a first diagonal element in the first switching circuit and a phase shift amount of a second diagonal element in the second switching circuit relative to the drive phase of a first reference element in the first switching circuit.

Abstract: A first switching circuit is connected between a transformer first winding and a DC power supply. A second switching circuit is connected between the transformer second winding and a battery. When charging the battery, a control circuit turns off an element in a second bridge circuit in the second switching circuit, and controls a phase shift amount of a first diagonal element, and a phase shift amount of a second diagonal element in the second bridge circuit, relative to a drive phase of a first reference element in a first bridge circuit in the first switching circuit. When discharging the battery, the control circuit turns off an element in the first bridge circuit and controls a phase shift amount of the second diagonal element and a phase shift amount of the first diagonal element relative to a drive phase of a second reference element in the second bridge circuit.

Abstract: In a DC/DC converter for bidirectional power transmission, a first switching circuit is connected between a first winding of a high-frequency transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. In the first and second switching circuits, capacitors are connected in parallel to semiconductor switching devices, and first and second reactors are connected on AC input/output lines. Upon power transmission, the switching circuit on the primary side of the high-frequency transformer performs zero voltage switching, and the switching circuit on the secondary side performs a step-up operation by using the reactor.

Abstract: A first DC/DC converter is provided between a rectifier for rectifying output of an electric generator driven by an engine, and a battery for supplying power to an in-vehicle load. An electric double layer capacitor and a second DC/DC converter for charge/discharge current control for the capacitor are provided between the rectifier and the first DC/DC converter. A control circuit sets a current target value which is a control target value for the second DC/DC converter, based on the voltage value of a battery bus, and when charging of the electric double layer capacitor is to be stopped based on a charge/discharge instruction signal, performs, before the charging is stopped, control of gradually attenuating the current target value for the second DC/DC converter, based on a voltage value VEDLC of the electric double layer capacitor.

Abstract: A first switching circuit is connected between a transformer first winding and a DC power supply. A second switching circuit is connected between the transformer second winding and a battery. When charging the battery, a control circuit turns off an element in a second bridge circuit in the second switching circuit, and controls a phase shift amount of a first diagonal element, and a phase shift amount of a second diagonal element in the second bridge circuit, relative to a drive phase of a first reference element in a first bridge circuit in the first switching circuit. When discharging the battery, the control circuit turns off an element in the first bridge circuit and controls a phase shift amount of the second diagonal element and a phase shift amount of the first diagonal element relative to a drive phase of a second reference element in the second bridge circuit.

Abstract: An inductor L2 is inserted in series between an input power supply E and a switching device Q1. An input smoothing capacitor C2 is provided between a connecting point of the inductor L2 and the switching device Q1 and a ground point. Herein, let L2 be an inductance value of the inductor, C2 be an electrostatic capacity of the input smoothing capacitor, and T1 be a time since the switching device Q1 is switched from an ON state to an OFF state until the switching device Q1 is switched to an ON state again according to an output signal from a drive circuit DR, then T1 is set so as to satisfy 0<T1<??{square root over (L2×C2)} By lowering a voltage applied to a switching device when the switching device switches OFF from ON, it becomes possible to use a switching device having low breakdown voltage in a step-down DC-to-DC converter.

Abstract: In a DC/DC converter for bidirectional power transmission, a first switching circuit is connected between a first winding of a high-frequency transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. In the first and second switching circuits, capacitors are connected in parallel to semiconductor switching devices, and first and second reactors are connected on AC input/output lines. Upon power transmission, the switching circuit on the primary side of the high-frequency transformer performs zero voltage switching, and the switching circuit on the secondary side performs a step-up operation by using the reactor.

Abstract: A first DC/DC converter (5) is of a constant voltage control type and is controlled so as to keep the voltage of an electric generation bus (A) at a predetermined target value. A second DC/DC converter (7) is of a constant current control type and is controlled so as to keep input current or output current at predetermined target current. A control circuit (8) determines an optimum target value Va* of electric generation bus voltage, based on different algorithms, in accordance with all or some of modes A to C which are classified by the charging/discharging condition of a second electric storage device (6), and controls the first DC/DC converter (5) so that the electric generation bus voltage Va becomes the determined target value Va*.

Abstract: A first DC/DC converter is provided between a rectifier for rectifying output of an electric generator driven by an engine, and a battery for supplying power to an in-vehicle load. An electric double layer capacitor and a second DC/DC converter for charge/discharge current control for the capacitor are provided between the rectifier and the first DC/DC converter. A control circuit sets a current target value which is a control target value for the second DC/DC converter, based on the voltage value of a battery bus, and when charging of the electric double layer capacitor is to be stopped based on a charge/discharge instruction signal, performs, before the charging is stopped, control of gradually attenuating the current target value for the second DC/DC converter, based on a voltage value VEDLC of the electric double layer capacitor.

Abstract: An inductor L2 is inserted in series between an input power supply E and a switching device Q1. An input smoothing capacitor C2 is provided between a connecting point of the inductor L2 and the switching device Q1 and a ground point. Herein, let L2 be an inductance value of the inductor, C2 be an electrostatic capacity of the input smoothing capacitor, and T1 be a time since the switching device Q1 is switched from an ON state to an OFF state until the switching device Q1 is switched to an ON state again according to an output signal from a drive circuit DR, then T1 is set so as to satisfy 0<T1<??{square root over (L2×C2)} By lowering a voltage applied to a switching device when the switching device switches OFF from ON, it becomes possible to use a switching device having low breakdown voltage in a step-down DC-to-DC converter.