Abstract: The power conversion device includes: a series unit composed of two switching elements; and a plurality of DC capacitors each connected in parallel to the series unit. The two switching elements and the plurality of DC capacitors are disposed in this order such that positive terminals and negative terminals thereof are aligned on a same side. Among busbars making connection between the respective DC capacitors and the switching elements, a busbar other than the busbar connected to the DC capacitor disposed at a farthest position has an inductance adjustment portion providing a bypass.

Abstract: A power converter is provided that includes a reactor that is improved in effect of cooling a core and a winding. The power converter includes: a cooling member having a first cooling surface; and a reactor including a core portion and a winding portion. The core portion is a rectangular parallelepiped and disposed on the first cooling surface that is larger in area than the core portion in a plan view. The winding is wound around the core portion and the cooling member. The power converter further includes a power conversion module connected to one end of the winding portion.

Abstract: In a power conversion device in which cell converters are connected in series, each cell converter includes: main circuit conductors connecting switching elements and a capacitor to each other; a bypass portion disposed between two external terminals connected to other cell converters; external output conductors connecting the external terminals and the main circuit conductors to each other; and bypass connection conductors connecting the external output conductors and the bypass portion to each other. The bypass connection conductors or the external output conductors are disposed so as to oppose each other at a high-potential side and a low-potential side thereof. The conductors are bent so as to have portions at which currents in parts of the conductors have the same direction. Thus, mutual inductances and self-inductances are increased, whereby short-circuit current flowing to the bypass portion at the time of double failures is suppressed.

Abstract: The power conversion device includes: a series unit composed of two switching elements; and a plurality of DC capacitors each connected in parallel to the series unit. The two switching elements and the plurality of DC capacitors are disposed in this order such that positive terminals and negative terminals thereof are aligned on a same side. Among busbars making connection between the respective DC capacitors and the switching elements, a busbar other than the busbar connected to the DC capacitor disposed at a farthest position has an inductance adjustment portion providing a bypass.

Abstract: A submodule includes a bridge circuit including two main power semiconductors connected in series for performing power conversion by on/off control and an electric energy storage element connected in parallel with a path of the two main power semiconductors connected in series, a bypass unit including a bypass power semiconductor), a bypass unit drive device to drive the bypass unit, a first external terminal, and a second external terminal. The first external terminal is connected to a node between the two main power semiconductors. The power conversion apparatus further includes an optical power-feed system for feeding power to the bypass unit drive device.

Abstract: A power converter is provided that includes a reactor that is improved in effect of cooling a core and a winding. The power converter includes: a cooling member having a first cooling surface; and a reactor including a core portion and a winding portion. The core portion is a rectangular parallelepiped and disposed on the first cooling surface that is larger in area than the core portion in a plan view. The winding is wound around the core portion and the cooling member. The power converter further includes a power conversion module connected to one end of the winding portion.

Abstract: In a power conversion device in which cell converters are connected in series, each cell converter includes: main circuit conductors connecting switching elements and a capacitor to each other; a bypass portion disposed between two external terminals connected to other cell converters; external output conductors connecting the external terminals and the main circuit conductors to each other; and bypass connection conductors connecting the external output conductors and the bypass portion to each other. The bypass connection conductors or the external output conductors are disposed so as to oppose each other at a high-potential side and a low-potential side thereof. The conductors are bent so as to have portions at which currents in parts of the conductors have the same direction. Thus, mutual inductances and self-inductances are increased, whereby short-circuit current flowing to the bypass portion at the time of double failures is suppressed.

Abstract: A submodule includes a bridge circuit including two main power semiconductors connected in series for performing power conversion by on/off control and an electric energy storage element connected in parallel with a path of the two main power semiconductors connected in series, a bypass unit including a bypass power semiconductor), a bypass unit drive device to drive the bypass unit, a first external terminal, and a second external terminal. The first external terminal is connected to a node between the two main power semiconductors. The power conversion apparatus further includes an optical power-feed system for feeding power to the bypass unit drive device.

Abstract: A power conversion apparatus includes: a plurality of cell blocks connected in cascade; and a plurality of bypass circuits each electrically connected in parallel with a corresponding one of the plurality of cell blocks. Each cell block includes: a first connection node on a high-potential side and a second connection node on a low-potential side for connection to another cell block; and a plurality of cell converters connected in cascade between the first connection node and the second connection node, each of the cell converters including an energy storage device. When a DC fault current flows in the direction from the low-potential side to the high-potential side, the current path via the plurality of cell blocks is larger in impedance than the current path via the plurality of bypass circuits.

Abstract: In a conversion circuit having a plurality of switching elements connected in series and parallel and a capacitor, the respective parts are connected by an external stacked conductor in which a P conductor connected to the positive electrode of the capacitor, an N conductor connected to the negative electrode of the capacitor (2), an AC conductor, and an even number of intermediate conductors connected between the plurality of switching elements, are stacked in plural layers. The respective switching elements are arranged such that the mutual positional relationship between the positive terminals and the negative terminals is the same as a direction of main current flowing through the external stacked conductor. The plurality of switching elements are arranged symmetrically with respect to a center line of the external stacked conductor which is in the same direction as the main current.

Abstract: In a conversion circuit having a plurality of switching elements connected in series and parallel and a capacitor, the respective parts are connected by an external stacked conductor in which a P conductor connected to the positive electrode of the capacitor, an N conductor connected to the negative electrode of the capacitor (2), an AC conductor, and an even number of intermediate conductors connected between the plurality of switching elements, are stacked in plural layers. The respective switching elements are arranged such that the mutual positional relationship between the positive terminals and the negative terminals is the same as a direction of main current flowing through the external stacked conductor. The plurality of switching elements are arranged symmetrically with respect to a center line of the external stacked conductor which is in the same direction as the main current.

Abstract: A first bridge circuit includes a first leg and a second leg. The first leg includes an upper arm and a lower arm. The upper arm includes a plurality of switching devices connected in series, a plurality of freewheeling diodes connected in antiparallel with the switching devices, respectively, and a plurality of snubber capacitors connected in parallel with the switching devices, respectively. A control circuit controls the first and second bridge circuits such that a dead time period is provided between a turn-on period of an upper arm and a turn-on period of a lower arm included in each of the first and second legs, in each of the first and second bridge circuits.

Abstract: A power conversion apparatus includes: a plurality of cell blocks connected in cascade; and a plurality of bypass circuits each electrically connected in parallel with a corresponding one of the plurality of cell blocks. Each cell block includes: a first connection node on a high-potential side and a second connection node on a low-potential side for connection to another cell block; and a plurality of cell converters connected in cascade between the first connection node and the second connection node, each of the cell converters including an energy storage device. When a DC fault current flows in the direction from the low-potential side to the high-potential side, the current path via the plurality of cell blocks is larger in impedance than the current path via the plurality of bypass circuits.

Abstract: A first bridge circuit includes a first leg and a second leg. The first leg includes an upper arm and a lower arm. The upper arm includes a plurality of switching devices connected in series, a plurality of freewheeling diodes connected in antiparallel with the switching devices, respectively, and a plurality of snubber capacitors connected in parallel with the switching devices, respectively. A control circuit controls the first and second bridge circuits such that a dead time period is provided between a turn-on period of an upper arm and a turn-on period of a lower arm included in each of the first and second legs, in each of the first and second bridge circuits.

Abstract: A power conversion apparatus includes a first power conversion circuit including a first switching element, a second power conversion circuit including a second switching element, a DC conductor which is provided in the first power conversion circuit and supplies a DC power to the first power conversion circuit, and a connection conductor which is provided in the first power conversion circuit, has a length having an inductance for inhibiting a flow of a ripple current caused by switching of the second switching element of the second power conversion circuit, and connects the DC conductor and the second power conversion circuit.

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: 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: 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 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.