Abstract: A motor drive device includes a bridge circuit 10 having a plurality of legs with switch elements 101 in upper and lower arms. High frequency AC voltage output from the bridge circuit 10, when it is connected to an AC power supply 1, is converted into a DC voltage via a transformer 21 and an AC/DC conversion circuit 11, thus charging the battery 2. Also, the DC voltage of the battery 2 is converted into an AC voltage by the bridge circuit 10 when the AC power supply 1 is cut off from the bridge circuit 10, and supplied to the alternating current motor 3. Because of this, the isolating transformer 21 can be driven at high frequency while the motor driving power conversion circuit is also used for battery charging, and a reduction in size and reduction in cost of the overall device are achieved.

Abstract: A DC-DC conversion device includes four semiconductor switch elements 101 to 104 in a full-bride configuration on the primary side of a transformer 2. With this configuration, it is possible to increase the turn ratio of a primary winding 21 and secondary winding 22 of the transformer 2 and thus increase a voltage V21 generated in the primary winding 21, and to decrease a current flowing through the primary winding 21 of the transformer 2 and thus decrease breaking currents of the semiconductor switch elements 101 to 104. Consequently, it is possible, by using an input voltage detection circuit 9 and an oscillator circuit 8, to prevent a decrease in power conversion efficiency particularly when an input DC voltage from a power source 1 is high and the switching frequencies of the semiconductor switch elements 101 to 104 are high.

Abstract: With a power conversion device, it is possible to lengthen the lifespan of a mechanical switch by preventing an absorption by the mechanical switch of induction energy accumulated in a reactor when there is a problem. When a mechanical switch is turned off when there is a problem, an absorption by the mechanical switch of induction energy accumulated in a reactor is prevented by the energy accumulated in the reactor being released to a capacitor via a diode, thus enabling a lengthening of the lifespan of the mechanical switch.

Abstract: A circuit of a full-bridge configuration using four semiconductor switch elements is used as a circuit on the primary side of a transformer in a DC-DC conversion device. With this configuration, it is possible to increase the turn ratio of a primary winding and a secondary winding of the transformer and thus increase a voltage generated in the primary winding, and to decrease a current flowing through the primary winding of the transformer and thus decrease breaking currents of the semiconductor switch elements.

Abstract: In some aspects of the invention, a power conversion device includes a semiconductor switch series circuit configured by connecting semiconductor switches in series, a capacitor series circuit configured by connecting capacitors in series, a reactor L connected between the series connection point of the semiconductor switches and the series connection point of the capacitors and a direct current power source connected in parallel to the capacitor. The semiconductor switch series circuit and capacitor series circuit are connected in parallel, a load is connected between the parallel connection points of the two circuits and the semiconductor switches are turned on and off, thereby raising a direct current power source voltage and supplying it to the load. By way of some aspects of the invention, it is possible to reduce the size and cost of a device.

Abstract: With a power conversion device, it is possible to lengthen the lifespan of a mechanical switch by preventing an absorption by the mechanical switch of induction energy accumulated in a reactor when there is a problem. When a mechanical switch is turned off when there is a problem, an absorption by the mechanical switch of induction energy accumulated in a reactor is prevented by the energy accumulated in the reactor being released to a capacitor via a diode, thus enabling a lengthening of the lifespan of the mechanical switch.

Abstract: An electric power converter includes a DC to DC converter section adjusting DC power of a battery with at least two units in series, a DC circuit having at least two DC link capacitors in series between a positive and a negative line from the DC to DC converter section, an electric power converter section connected to the DC circuit to convert DC electric power to AC electric power for a motor, a bilateral switching circuit connecting an intermediate potential point between the capacitors and an AC output point in the electric power converter section, and a short-circuit between the intermediate potential point of the DC circuit and an intermediate potential point between the battery units. Normal operation of a load is ensured even when the battery, the capacitor in the DC circuit or the switching device in the electric power converter section becomes abnormal, while achieving high efficiency.

Abstract: In an AC motor driving circuit, a current-type rectifier circuit having a filter circuit and first bidirectional switches bridge-connected to the filter circuit is provided in an output of an AC power supply. An AC motor is connected to an output of the rectifier circuit through a voltage-type inverter. One terminal of each of second bidirectional switches is connected to corresponding one of output terminals of the current-type rectifier circuit. The other terminals of the second bidirectional switches are collectively connected to one terminal of a series circuit having a DC power supply and a reactor. The other terminal of the series circuit is connected to one output terminal of the current-type rectifier circuit. With this configuration, a large capacitor for a DC link can be dispensed with, so that a reduction in circuit size and weight can be attained.

Abstract: In an AC motor driving circuit from an AC power supply and a DC power supply, a matrix converter and a power conversion circuit are provided. The matrix converter is connected between an output of the AC power supply and an input of the AC motor. In the power conversion circuit, switches back-to-back connected to diodes, and bidirectional switches are series-connected, respectively. Connection junctions between the switches and the bidirectional switches are connected to the input phases of the AC motor, respectively. The other terminal of each switch is connected to one terminal of the DC power supply while the other terminal of each bidirectional switch is connected to the other terminal of the DC power supply. In this manner, the number of switches through which electric power passes at the time of operation is reduced so that loss can be reduced. Accordingly, power conversion efficiency can be improved.

Abstract: An electric power converter facilitates performing soft switching in the two-way electric-power-conversion operation thereof, and reducing the manufacturing costs thereof and the losses caused therein, The electric power converter includes a first switching device; a second switching device; a first series circuit including capacitor, a diode, the primary winding of transformer, and a third switching device; a second series circuit including a capacitor, a fourth switching device, the primary winding of transformer, and a diode; a third series circuit including a diode and the secondary winding of transformer; and a voltage clamping element connected in parallel to the primary winding of transformer. The first series circuit is connected in parallel to the first switching device, and the second series circuit is connected in parallel to second switching device. The third series circuit is connected between the DC output terminals.

Abstract: In an AC motor driving circuit, a current source rectifier is provided on the output side of an AC generator and an AC motor is connected to the output side of the current source rectifier through a voltage source inverter. Along with this, one of terminals of each of a plurality of bidirectional switches is connected to its corresponding output terminal of the voltage source inverter, the other terminals of a plurality of the bidirectional switches are lumped together to be connected to one of terminals of a storage battery, and the other terminal of the storage battery is connected to one of DC input terminals of the voltage source inverter. This eliminates need for a large capacitor at a DC link and a reactor in a chopper which were previously necessary, by which the AC motor driving circuit is downsized.

Abstract: An electric power converter facilitates performing soft switching in the two-way electric-power-conversion operation thereof, and reducing the manufacturing costs thereof and the losses caused therein, The electric power converter includes a first switching device; a second switching device; a first series circuit including capacitor, a diode, the primary winding of transformer, and a third switching device; a second series circuit including a capacitor, a fourth switching device, the primary winding of transformer, and a diode; a third series circuit including a diode and the secondary winding of transformer; and a voltage clamping element connected in parallel to the primary winding of transformer. The first series circuit is connected in parallel to the first switching device, and the second series circuit is connected in parallel to second switching device. The third series circuit is connected between the DC output terminals.

Abstract: A current source rectifier is provided at an output of an alternating current generator, an alternating current motor is connected to an output of the rectifier via a voltage source inverter, furthermore, two arms having switching elements connected in inverse parallel to diodes are connected to the output of the rectifier, and one terminal of a direct current power source capable of a power supply and absorption is connected to a midpoint between the arms, while the other terminal thereof is connected to a neutral point of motor coils or generator coils, thereby eliminating a need for a large volumetric reactor in a direct current chopper, achieving a downsizing of the circuit.

Abstract: An electric power supply system for driving an electric rotating machine has a generator supplied with driving power from an engine to generate alternating-current electric power and a matrix converter as an alternating-current to alternating-current direct converter supplied with the alternating-current electric power to output arbitrary alternating-current electric power. By driving a motor with the alternating-current electric power supplied from the matrix converter, only one time electric power conversion is carried out to provide high efficiency in the whole system. In addition, electric power loss can be reduced so as to enhance a motor output when the system is applied to a vehicle power supply system.

Abstract: An electric power converter includes a DC to DC converter section adjusting DC power of a battery with at least two units in series, a DC circuit having at least two DC link capacitors in series between a positive and a negative line from the DC to DC converter section, an electric power converter section connected to the DC circuit to convert DC electric power to AC electric power for a motor, a bilateral switching circuit connecting an intermediate potential point between the capacitors and an AC output point in the electric power converter section, and a short-circuit between the intermediate potential point of the DC circuit and an intermediate potential point between the battery units. Normal operation of a load is ensured even when the battery, the capacitor in the DC circuit or the switching device in the electric power converter section becomes abnormal, while achieving high efficiency.

Abstract: In an AC motor driving circuit, a current-type rectifier circuit having a filter circuit and first bidirectional switches bridge-connected to the filter circuit is provided in an output of an AC power supply. An AC motor is connected to an output of the rectifier circuit through a voltage-type inverter. One terminal of each of second bidirectional switches is connected to corresponding one of output terminals of the current-type rectifier circuit. The other terminals of the second bidirectional switches are collectively connected to one terminal of a series circuit having a DC power supply and a reactor. The other terminal of the series circuit is connected to one output terminal of the current-type rectifier circuit. With this configuration, a large capacitor for a DC link can be dispensed with, so that a reduction in circuit size and weight can be attained.

Abstract: In an AC motor driving circuit from an AC power supply and a DC power supply, a matrix converter and a power conversion circuit are provided. The matrix converter is connected between an output of the AC power supply and an input of the AC motor. In the power conversion circuit, switches back-to-back connected to diodes, and bidirectional switches are series-connected, respectively. Connection junctions between the switches and the bidirectional switches are connected to the input phases of the AC motor, respectively. The other terminal of each switch is connected to one terminal of the DC power supply while the other terminal of each bidirectional switch is connected to the other terminal of the DC power supply. In this manner, the number of switches through which electric power passes at the time of operation is reduced so that loss can be reduced. Accordingly, power conversion efficiency can be improved.

Abstract: In an AC motor driving circuit, a current source rectifier is provided on the output side of an AC generator and an AC motor is connected to the output side of the current source rectifier through a voltage source inverter. Along with this, one of terminals of each of a plurality of bidirectional switches is connected to its corresponding output terminal of the voltage source inverter, the other terminals of a plurality of the bidirectional switches are lumped together to be connected to one of terminals of a storage battery, and the other terminal of the storage battery is connected to one of DC input terminals of the voltage source inverter. This eliminates need for a large capacitor at a DC link and a reactor in a chopper which were previously necessary, by which the AC motor driving circuit is downsized.

Abstract: An electric power converter facilitates performing soft switching in the two-way electric-power-conversion operation thereof, and reducing the manufacturing costs thereof and the losses caused therein, The electric power converter includes a first switching device; a second switching device; a first series circuit including capacitor, a diode, the primary winding of transformer, and a third switching device; a second series circuit including a capacitor, a fourth switching device, the primary winding of transformer, and a diode; a third series circuit including a diode and the secondary winding of transformer; and a voltage clamping element connected in parallel to the primary winding of transformer. The first series circuit is connected in parallel to the first switching device, and the second series circuit is connected in parallel to second switching device. The third series circuit is connected between the DC output terminals.

Abstract: A current source rectifier is provided at an output of an alternating current generator, an alternating current motor is connected to an output of the rectifier via a voltage source inverter, furthermore, two arms having switching elements connected in inverse parallel to diodes are connected to the output of the rectifier, and one terminal of a direct current power source capable of a power supply and absorption is connected to a midpoint between the arms, while the other terminal thereof is connected to a neutral point of motor coils or generator coils, thereby eliminating a need for a large volumetric reactor in a direct current chopper, achieving a downsizing of the circuit.