Abstract: Three or more circuits, in which series-connected low-voltage and high-voltage side switches including MOSFETs including parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors, are connected in series. One of elementary series circuits, each including a capacitor and an inductor, is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit by a period of time not exceeding a time period equal to (period of resonance)/2. A resonance phenomenon of the capacitor and the inductor is used and conduction loss in the rectifier circuits is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor.

Abstract: Three or more circuits including a driving inverter circuit and rectifier circuits are connected in series, each of the circuits including a high-voltage side MOSFET and a low-voltage side MOSFET connected in series as well as a smoothing capacitor having positive and negative terminals between which the MOSFETs are connected. LC series circuits, each including a capacitor and an inductor, are disposed individually between one specific circuit and the other circuits with periods of resonance of the LC series circuits made equal to one another. In performing DC/DC power conversion through charging and discharging operation of the capacitors, a resonance phenomenon of the LC series circuits is used to improve conversion efficiency and achieve a reduction in size of the apparatus structure.

Abstract: A power supply apparatus includes: an AC generator including an AC generating section, and a rectifier for rectifying an AC voltage generated in the AC generating section, and outputting a DC voltage; and a DC/DC converter for converting the output voltage of the rectifier into a DC voltage having a different voltage value, wherein the output voltage of the rectifier is set to be larger than the output voltage of the DC/DC converter in accordance with the rotation speed of the AC generating section and the amount of power supply to an electrical load connected to the DC/DC converter, and is stepped down and outputted by using the DC/DC converter. The power supply apparatus is capable of increasing an output power efficiently.

Abstract: In a power conversion device which performs DC/DC conversion, an inverter circuit (20), which is formed of one or more single-phase inverters (20a) and (20b) connected in series to each other, is connected in series to a DC power supply (1) in its subsequent stage. In further subsequent stage, a smoothing capacitor (6) connected to the inverter circuit (20) via a rectifier diode (5), and a shorting switch (4) which bypasses the smoothing capacitor (6) are provided. The shorting switch (4) is switched ON to charge capacitors (25) and (35) included in the single-phase inverter (20a) and (20b), respectively, whereas the shorting switch (4) is switched OFF to discharge the capacitors (25) and (35), whereby the voltage of the smoothing capacitor (6) is controlled.

Abstract: To obtain a gate driving circuit in which rising of a constant current of a constant current circuit is fast and power saving is achieved, the gate driving circuit includes: a constant current driving circuit (28) for supplying a constant current; a gate terminal of a power semiconductor element (1), which is connected to an output terminal of the constant current driving circuit; a comparator (22) for comparing a voltage at the gate terminal with a predetermined voltage value and outputting a signal indicating that the voltage is higher than the predetermined voltage value; and a driving control section (20) for increasing a current from the constant current driving circuit in response to a signal for turning on the power semiconductor element, and reducing the current from the constant current driving circuit in response to the signal from the comparator.

Abstract: Even when one of IGBTs fails in a semiconductor power converter apparatus in which a plurality of semiconductor elements are connected in parallel, the remaining IGBT(s) is prevented from failing with a simple circuit configuration. The semiconductor power converter apparatus includes: a semiconductor power conversion circuit in which a first IGBT having a temperature sensing unit and a second IGBT having a current sensing unit are connected in parallel, for causing the first and second semiconductor elements to perform switching operations; an overheat protection circuit for performing overheat protection for the first and second IGBTs based on temperature information obtained from the temperature sensing unit of the first IGBT; and an overcurrent protection circuit for performing overcurrent protection for the first and second IGBTs based on current information obtained from the current sensing unit of the second IGBT.

Abstract: Three or more circuits including a driving inverter circuit and rectifier circuits are connected in series, each of the circuits including a high-voltage side MOSFET and a low-voltage side MOSFET connected in series as well as a smoothing capacitor having positive and negative terminals between which the MOSFETs are connected. LC series circuits, each including a capacitor and an inductor, are disposed individually between one specific circuit and the other circuits with periods of resonance of the LC series circuits made equal to one another. In performing DC/DC power conversion through charging and discharging operation of the capacitors, a resonance phenomenon of the LC series circuits is used to improve conversion efficiency and achieve a reduction in size of the apparatus structure.

Abstract: A DC/DC power conversion device includes n-stage circuits comprised of an inverter circuit for driving which is connected between positive terminals and negative terminals of smoothing capacitors, and a rectifier circuit which is connected between positive terminals and negative terminals of smoothing capacitors; a first circuit corresponding to at least one among the n-stage circuits and configured by connecting in parallel cell circuits of m, second circuits corresponding to a plurality of remaining circuits of (n?1) among the n-stage circuits; capacitors for energy transfer connected between middle points of the cell circuits and middle points of the second circuits; and column circuits of m comprised of the cell circuits, the second circuits and the capacitors for energy transfer, wherein the middle points are contact points of high voltage sided elements and low voltage sided elements of the cell circuits and the second circuits; and driving signals for driving the respective column circuits have the sam

Abstract: Three or more circuits, in which series-connected low-voltage and high-voltage side switches including MOSFETs including parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors, are connected in series. One of elementary series circuits, each including a capacitor and an inductor, is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit by a period of time not exceeding a time period equal to (period of resonance)/2. A resonance phenomenon of the capacitor and the inductor is used and conduction loss in the rectifier circuits is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor.

Abstract: A gate drive apparatus including a constant-current-pulse gate drive circuit which creates a gate signal for a switching device as a constant-current output, a constant-voltage-pulse gate drive circuit which creates the gate signal as a constant-voltage output, and a decision/switch circuit which switches the operation of the constant-current-pulse gate drive circuit and the operation of the constant-voltage-pulse gate drive circuit. The variance of switching speeds attributed to the variances of threshold voltages and mirror voltages in a plurality of switching devices which are driven by the gate drive apparatus can be suppressed, and the variance of losses can be minimized.

Abstract: A DC/DC power conversion device includes n-stage circuits comprised of an inverter circuit for driving which is connected between positive terminals and negative terminals of smoothing capacitors, and a rectifier circuit which is connected between positive terminals and negative terminals of smoothing capacitors; a first circuit corresponding to at least one among the n-stage circuits and configured by connecting in parallel cell circuits of m, second circuits corresponding to a plurality of remaining circuits of (n?1) among the n-stage circuits; capacitors for energy transfer connected between middle points of the cell circuits and middle points of the second circuits; and column circuits of m comprised of the cell circuits, the second circuits and the capacitors for energy transfer, wherein the middle points are contact points of high voltage sided elements and low voltage sided elements of the cell circuits and the second circuits; and driving signals for driving the respective column circuits have the sam

Abstract: This invention provides a power unit for an automobile including a motor 6 for starting an engine by transmitting a power thereto and generating a power by receiving a power from the engine during rotation thereof, a power converting circuit 5 for transmitting a power to the motor 6, a battery 1, an energy storing source 20 for storing energy, and a DC/DC converter including at least two switching elements 10, 11, charging the energy storing source 20, and recovering energy in the energy storing source 20 to the battery 1. Since the switch provided in the DC/DC converter is normally turned on when the motor 6 generates power by receiving a power from the engine and charges the battery 1 through the power converting circuit 5 and the DC/DC converter, generation of heat from the DC/DC converter circuit part can be suppressed greatly.

Abstract: A motor driving apparatus makes a carrier signal of an inverter be synchronized with a carrier signal of a DC/DC converter, and determines a phase difference between both the carrier signals based on a ratio of an input voltage inputted to the DC/DC converter and an input voltage inputted to the inverter, and a percentage of modulation and a power factor which are operation parameters of the inverter. When the frequency of the carrier signal of the DC/DC converter is set to be twice as high as that of the carrier signal of the inverter, an optimal phase difference is determined based on the ratio of the input voltage of the DC/DC converter and the input voltage of the inverter.

Abstract: A motor driving apparatus is provided which can minimize ripple current flowing through a DC link capacitor, and downsize the motor driving apparatus. It synchronizes the frequency of the inverter carrier signal for driving an inverter with the frequency of the DC/DC converter carrier signal for driving a DC/DC converter, and carries out control in such a manner that the center of a period during which the input current of the inverter is zero and the center of a period during which the output current of the DC/DC converter is zero are matched.

Abstract: Even when one of IGBTs fails in a semiconductor power converter apparatus in which a plurality of semiconductor elements are connected in parallel, the remaining IGBT(s) is prevented from failing with a simple circuit configuration. The semiconductor power converter apparatus includes: a semiconductor power conversion circuit in which a first IGBT having a temperature sensing unit and a second IGBT having a current sensing unit are connected in parallel, for causing the first and second semiconductor elements to perform switching operations; an overheat protection circuit for performing overheat protection for the first and second IGBTs based on temperature information obtained from the temperature sensing unit of the first IGBT; and an overcurrent protection circuit for performing overcurrent protection for the first and second IGBTs based on current information obtained from the current sensing unit of the second IGBT.

Abstract: A power circuit for a battery for, even when an idle-stop operation is continuously performed, preventing reduction of an electric power supplied to a motor at start-up to obtain a set engine rpm. The power circuit includes a series-connected power supply in which a battery having a load and a capacitor group are connected in series with each other, a DC/DC converter for shifting electric power between the battery and the capacitor group, and between the battery and the load, and a controller for controlling the DC/DC converter. The controller detects the voltage of the capacitor group, and when the voltage detected is lower than a first threshold voltage, controls the DC/DC converter so that the capacitor group is charged with electricity.

Abstract: A motor driving apparatus makes a carrier signal of an inverter be synchronized with a carrier signal of a DC/DC converter, and determines a phase difference between both the carrier signals based on a ratio of an input voltage inputted to the DC/DC converter and an input voltage inputted to the inverter, and a percentage of modulation and a power factor which are operation parameters of the inverter. When the frequency of the carrier signal of the DC/DC converter is set to be twice as high as that of the carrier signal of the inverter, an optimal phase difference is determined based on the ratio of the input voltage of the DC/DC converter and the input voltage of the inverter.

Abstract: The invention provides an apparatus for bi-directional power conversion between a DC circuit and an AC circuit, which inexpensively and simply suppresses generation losses of elements and reduces heat generation, wherein a voltage obtained by dividing the U-phase voltage Vu is compared with a voltage obtained by dividing the voltage vpn of a DC circuit by a comparator CP1, and the MOSFET UFETh is turned on at the output timing thereof, and a voltage obtained by dividing the V-phase voltage Vv is compared with a voltage obtained by dividing the voltage Vpn of a DC circuit by a comparator CP2, and the MOSFET UFETh is turned off at the output timing thereof.

Abstract: A power circuit for a battery for, even when an idle-stop operation is continuously performed, preventing reduction of an electric power supplied to a motor at start-up to obtain a set engine rpm. The power circuit includes a series-connected power supply in which a battery having a load and a capacitor group are connected in series with each other, a DC/DC converter for shifting electric power between the battery and the capacitor group, and between the battery and the load, and a controller for controlling the DC/DC converter. The controller detects the voltage of the capacitor group, and when the voltage detected is lower than a first threshold voltage, controls the DC/DC converter so that the capacitor group is charged with electricity.

Abstract: A power circuit for a battery for, even when an idle-stop operation is continuously performed, preventing reduction of an electric power supplied to a motor at start-up to obtain a set engine rpm. The power circuit includes a series-connected power supply in which a battery having a load and a capacitor group are connected in series with each other, a DC/DC converter for shifting electric power between the battery and the capacitor group, and between the battery and the load, and a controller for controlling the DC/DC converter. The controller detects the voltage of the capacitor group, and when the voltage detected is lower than a first threshold voltage, controls the DC/DC converter so that the capacitor group is charged with electricity.