Abstract: A converter includes a first diode (D1) having its anode and cathode connected to input terminal (T0) and a first output terminal (T1), respectively, a second diode (D2) having its anode and cathode connected to a second output terminal (T2) and an input terminal (T0), respectively, and a bidirectional switch connected between the input terminal (T0) and a third output terminal (T3). The bidirectional switch includes third to sixth diodes (D3 to D6) and a transistor (Q1). The first diode (D1), the second diode (D2), and the transistor (Q) are each formed of a wide-bandgap semiconductor, and the third to sixth diodes (D3 to D6) are each formed of a semiconductor other than wide-bandgap semiconductors.

Abstract: An electric power conversion device includes a first arm and a second arm each including converter cells. The converter cell of the first arm is a first converter cell having a full-bridge configuration including an energy storing element and semiconductor switching elements. The converter cell of the second arm is a second converter cell having a half-bridge configuration including an energy storing element and semiconductor switching elements. Thus, short-circuit current between DC terminals is suppressed.

Abstract: A converter includes a first diode (D1) having its anode and cathode connected to input terminal (T0) and a first output terminal (T1), respectively, a second diode (D2) having its anode and cathode connected to a second output terminal (T2) and an input terminal (T0), respectively, and a bidirectional switch connected between the input terminal (T0) and a third output terminal (T3). The bidirectional switch includes third to sixth diodes (D3 to D6) and a transistor (Q1). The first diode (D1), the second diode (D2), and the transistor (Q) are each formed of a wide-bandgap semiconductor, and the third to sixth diodes (D3 to D6) are each formed of a semiconductor other than wide-bandgap semiconductors.

Abstract: In an electric power conversion device which performs power conversion between multiphase AC and DC, a first converter cell of a first arm for each phase of a power converter includes: a capacitor; a Leg A having upper and lower arms having switching elements; and a Leg B having upper and lower arms one of which has a switching element and the other of which has only a diode, and a second converter cell of a second arm includes: a capacitor; and a Leg Aa having upper and lower arms having switching elements. A control device has a steady mode and a protection mode. When short-circuit between DC terminals of the power converter is detected, the control device switches from the steady mode to the protection mode, turns off all the switching elements of the first converter cell of the first arm, and controls the second converter cell of the second arm so as to perform reactive power compensation operation.

Abstract: A power conversion device including: an energy storage unit which receives and stores voltage of a self-power-feeding device; and a bypass unit drive device which, when voltage of the self-power-feeding device becomes smaller than a predetermined lower limit value, causes a bypass unit to perform short-circuiting operation by power stored in the energy storage unit. Thus, by appropriately setting the above voltage lower limit value as a threshold value for the short-circuiting operation, it becomes possible to swiftly and reliably perform short-circuiting protection operation even if a cell converter has failed, thus it is possible to always safely continue the operation of the power conversion device.

Abstract: An electrical power converter includes: AC voltage terminals U, V, and W; DC voltage terminals P and N; a converter cell series unit composed of one or more converter cells connected in series between the AC voltage terminals U, V, and W and the DC voltage terminals P and N, each converter cell including a semiconductor element and a capacitor; and a first inductance connected in series to the converter cell series unit, between, of the DC voltage terminals P and N, a DC voltage terminal at the lowest potential with respect to the ground, and the AC voltage terminals U, V, and W.

Abstract: A converter includes: a first transistor (Q1) connected between a first output terminal (T1) and an input terminal (T0); a second transistor (Q2) connected between the input terminal (T0) and a second output terminal (T2); first and second diodes (D1, D2) connected in anti-parallel to the first and second transistors (Q1, Q2), respectively; and a bidirectional switch that is connected between the input terminal (T0) and a third output terminal (T3) and that includes third and fourth transistors (Q3, Q4) and third and fourth diodes (D3, D4). The first and second diodes (D1, D2) and the third and fourth transistors (Q3, Q4) each are formed of a wide band gap semiconductor. The third and fourth diodes (D3, D4) and the first and second transistors (Q1, Q2) each are formed of a semiconductor other than the wide band gap semiconductor.

Abstract: An inverter includes: a first transistor (Q1) connected between a first input terminal (T1) and an output terminal (T4); a second transistor (Q2) connected between the output terminal (T4) and a second input terminal (T2); first and second diodes (D1, D2) connected in anti-parallel to the first and second transistors (Q1, Q2), respectively; and a bidirectional switch that is connected between a third input terminal (T3) and the output terminal (T4) and that includes third and fourth transistors (Q3, Q4) and third and fourth diodes (D3, D4). The first and second transistors (Q1, Q2) and the third and fourth diodes (D3, D4) are each formed of a wide band gap semiconductor. The third and fourth transistors (Q3, Q4) and the first and second diodes (D1, D2) are each formed of a semiconductor other than the wide band gap semiconductor.

Abstract: A power conversion device includes transformers provided with primary windings connected to input terminals and secondary windings including pluralities of single-phase open windings that are insulated to each other; a plurality of converter cells connected to the secondary windings of the transformers; and a control circuit for controlling ON/OFF of switching elements. The converter cells are each include a converter and the inverter that are provided with the switching elements, in which their input ends are connected to the respective single-phase open windings, so that the input ends are connected in mutually parallel fashion, through the transformers, to the input terminal of each phase, and in which their output ends are connected in mutually serial fashion to an output terminal of each phase, to thereby perform three or more-level power conversion.

Abstract: A power conversion device including: an energy storage unit which receives and stores voltage of a self-power-feeding device; and a bypass unit drive device which, when voltage of the self-power-feeding device becomes smaller than a predetermined lower limit value, causes a bypass unit to perform short-circuiting operation by power stored in the energy storage unit. Thus, by appropriately setting the above voltage lower limit value as a threshold value for the short-circuiting operation, it becomes possible to swiftly and reliably perform short-circuiting protection operation even if a cell converter has failed, thus it is possible to always safely continue the operation of the power conversion device.

Abstract: An electric power conversion device includes a plurality of cell converters connected in cascade and including main circuits, drive circuits, and self-feeding devices for supplying power to the drive circuits by being supplied with power from the main circuits. The drive circuit is supplied with power via a first feed line from the self-feeding device in the corresponding cell converter, and supplied with power from the self-feeding device in another cell converter via a second feed line on which an insulation input/output circuit is provided. When the self-feeding device is abnormal, the drive circuit is supplied with power from the self-feeding device in the other cell converter, whereby the electric power conversion device continuously provides a desired output.

Abstract: Four bus bars, which are two positive-electrode-side bus bars connecting a positive electrode of a capacitor series circuit and a positive electrode of a power conversion section, a negative-electrode-side bus bar connecting a negative electrode of the capacitor series circuit and a negative electrode of the power conversion section, and an intermediate connection bus bar connecting in series two smoothing capacitors in the capacitor series circuit, are stacked in close contact with one another via insulating layers, to form a 4-layer bus bar. The two positive-electrode-side bus bars are not adjacent to each other and are connected in parallel to each other. The positive-electrode-side bus bar which is one of them and the negative-electrode-side bus bar are disposed adjacent to each other, thereby to reduce DC wiring inductances of the wiring structure in which the capacitor series circuit and the power conversion section are connected.

Abstract: A power conversion device in which a plurality of converter cells are connected in series with one another. The converter cells each include two or more semiconductor devices, an energy storage element and a bypass element including a constituent element for setting the bypass element to be close-circuited by detecting abnormality of a converter cell, and including a constituent element for controlling, among the semiconductor devices, a semiconductor device connected in parallel with the bypass element to set in a turn-on state, at the same time when the bypass element is set close-circuited or in advance of its close circuit.

Abstract: Phase arms each having one or more converter cells connected in series are provided between AC terminals U, V, W and DC terminals P and N. At least one of the converter cells is a first converter cell in which an energy accumulating element, a first leg, and a second leg are connected in parallel. The first leg has upper and lower arms both having semiconductor switching elements. The second leg has upper and lower arms one of which has a diode and the other one of which has a semiconductor switching element.

Abstract: An electric power conversion device includes a plurality of cell converters connected in cascade and including main circuits, drive circuits, and self-feeding devices for supplying power to the drive circuits by being supplied with power from the main circuits. The drive circuit is supplied with power via a first feed line from the self-feeding device in the corresponding cell converter, and supplied with power from the self-feeding device in another cell converter via a second feed line on which an insulation input/output circuit is provided. When the self-feeding device is abnormal, the drive circuit is supplied with power from the self-feeding device in the other cell converter, whereby the electric power conversion device continuously provides a desired output.

Abstract: Four bus bars, which are two positive-electrode-side bus bars connecting a positive electrode of a capacitor series circuit and a positive electrode of a power conversion section, a negative-electrode-side bus bar connecting a negative electrode of the capacitor series circuit and a negative electrode of the power conversion section, and an intermediate connection bus bar connecting in series two smoothing capacitors in the capacitor series circuit, are stacked in close contact with one another via insulating layers, to form a 4-layer bus bar. The two positive-electrode-side bus bars are not adjacent to each other and are connected in parallel to each other. The positive-electrode-side bus bar which is one of them and the negative-electrode-side bus bar are disposed adjacent to each other, thereby to reduce DC wiring inductances of the wiring structure in which the capacitor series circuit and the power conversion section are connected.

Abstract: A cell block including a plurality of cell converters connected in cascade and each including switching elements and a capacitor is provided. The cell block includes external connection terminals for connecting to another cell block in cascade, and a bypass circuit is connected to the external connection terminals.

Abstract: Wiring between semiconductor modules and a direct current power supply circuit, which construct a three-level power conversion apparatus, is made to be low inductance, so reduction in size and cost can be attained easily. In cases where a connection is made between direct current power supplies (electrolytic capacitors) and IGBT modules of a three-level inverter, a wiring conductor for a bi-directional switch part is divided into three conductors or two conductors on a same surface, and these conductors are sandwiched by a P conductor and an N conductor, which are arranged at outer sides thereof, respectively, through insulating materials, so a three-layer wiring structure of a sealed structure is formed. As a result, wiring inductance can be made small even with a small number of laminated layers, so that the reduction in size and cost of the apparatus as a whole is achieved.

Abstract: A power conversion device includes transformers provided with primary windings connected to input terminals and secondary windings including pluralities of single-phase open windings that are insulated to each other; a plurality of converter cells connected to the secondary windings of the transformers; and a control circuit for controlling ON/OFF of switching elements. The converter cells are each include a converter and the inverter that are provided with the switching elements, in which their input ends are connected to the respective single-phase open windings, so that the input ends are connected in mutually parallel fashion, through the transformers, to the input terminal of each phase, and in which their output ends are connected in mutually serial fashion to an output terminal of each phase, to thereby perform three or more-level power conversion.

Abstract: An electrical power converter includes: AC voltage terminals U, V, and W; DC voltage terminals P and N; a converter cell series unit composed of one or more converter cells connected in series between the AC voltage terminals U, V, and W and the DC voltage terminals P and N, each converter cell including a semiconductor element and a capacitor; and a first inductance connected in series to the converter cell series unit, between, of the DC voltage terminals P and N, a DC voltage terminal at the lowest potential with respect to the ground, and the AC voltage terminals U, V, and W.