Abstract: An aspect of the present disclosure is a power conversion device including: a primary-side transformer to which a primary AC voltage is input from a primary-side circuit; and a secondary-side transformer that outputs a secondary AC voltage lower than the primary AC voltage to a secondary-side circuit. The primary-side transformer includes a primary-side primary winding to which the primary AC voltage is input, and a primary-side secondary winding to which power is transmitted from the primary-side primary winding. The secondary-side transformer includes a secondary-side primary winding constituting a closed circuit together with the primary-side secondary winding, and a secondary-side secondary winding to which power is transmitted from the secondary-side primary winding and which outputs the secondary AC voltage. The primary-side circuit and the closed circuit are connected to a common potential.

Abstract: To provide a semiconductor device signal transmission circuit for drive-control, a method of controlling a semiconductor device signal transmission circuit for drive-control, a semiconductor device, a power conversion device, and an electric system for a railway vehicle capable of preventing malfunction due to noise while speeding up or reducing loss of a switching operation. The semiconductor device signal transmission circuit for drive-control that is connected between a semiconductor device constituting an arm in a power conversion device and a drive circuit configured to drive the semiconductor device, including: an inductor; and an impedance circuit including a switch and connected in parallel with the inductor.

Abstract: An object of the present invention is to sufficiently reduce a switching loss. A control device causes a positive electrode of a first voltage to appear at a second connection point by switching second and third switching elements to an ON state. Next, the control device causes the positive electrode of the first voltage to appear at a first connection point by switching the second and third switching elements to an OFF state. After that, fifth and eighth switching elements are switched to the OFF state, and sixth and seventh switching elements are switched to the ON state.

Abstract: In order to provide a transformer and an electric power converter which are less likely to become deteriorated with time and which have stable insulation performance, the transformer according to the present invention is provided with: a core; a bobbin in which a low-voltage-side primary winding and a high-voltage-side secondary winding are disposed along the central magnetic leg of the core; and a bobbin support part that supports the bobbin at an end of the bobbin on the primary winding side, such that an air gap is provided between the central magnetic leg of the core and a surface of the bobbin corresponding to the secondary winding.

Abstract: A power conversion device that suppresses voltage pulsation of a capacitor of a power converter with respect to a control target whose effective power is to be controlled is provided. The power conversion device includes a plurality of power conversion cells that are connected to each other, and convert a primary-side system voltage into a secondary-side system voltage, a capacitor that is connected to each of the plurality of power conversion cells, and a power conversion cell driver that drives the power conversion cells to add a 3N order higher-harmonic-wave voltage of each of alternating voltages of the plurality of power conversion cells to the each of alternating voltages, and output a voltage made by adding the each of alternating voltages and the 3N order higher-harmonic-wave voltage, when N is a natural number.

Abstract: An object of the present invention is to sufficiently reduce a switching loss. A control device causes a positive electrode of a first voltage to appear at a second connection point by switching second and third switching elements to an ON state. Next, the control device causes the positive electrode of the first voltage to appear at a first connection point by switching the second and third switching elements to an OFF state. After that, fifth and eighth switching elements are switched to the OFF state, and sixth and seventh switching elements are switched to the ON state.

Abstract: In order to provide a transformer and an electric power converter which are less likely to become deteriorated with time and which have stable insulation performance, the transformer according to the present invention is provided with: a core; a bobbin in which a low-voltage-side primary winding and a high-voltage-side secondary winding are disposed along the central magnetic leg of the core; and a bobbin support part that supports the bobbin at an end of the bobbin on the primary winding side, such that an air gap is provided between the central magnetic leg of the core and a surface of the bobbin corresponding to the secondary winding.

Abstract: To provide a semiconductor device signal transmission circuit for drive-control, a method of controlling a semiconductor device signal transmission circuit for drive-control, a semiconductor device, a power conversion device, and an electric system for a railway vehicle capable of preventing malfunction due to noise while speeding up or reducing loss of a switching operation. The semiconductor device signal transmission circuit for drive-control that is connected between a semiconductor device constituting an arm in a power conversion device and a drive circuit configured to drive the semiconductor device, including: an inductor; and an impedance circuit including a switch and connected in parallel with the inductor.

Abstract: Provided is a power conversion device which can be configured inexpensively and in which initial charging can be performed quickly. Accordingly, the power conversion device is provided with: a power conversion device cell having a first converter for converting a first AC voltage to a first DC voltage, a second converter for converting the first DC voltage to another voltage, and a first capacitor charged by the first DC voltage; and a control circuit for allowing charging of the first capacitor while changing the operational state of the first converter in accordance with the first DC voltage.

Abstract: Provided is a power conversion device which can be configured inexpensively and in which initial charging can be performed quickly. Accordingly, the power conversion device is provided with: a power conversion device cell having a first converter for converting a first AC voltage to a first DC voltage, a second converter for converting the first DC voltage to another voltage, and a first capacitor charged by the first DC voltage; and a control circuit for allowing charging of the first capacitor while changing the operational state of the first converter in accordance with the first DC voltage.

Abstract: A power conversion device includes: power conversion cells; and a controller to control the cells. Each cell includes: a transformer; a primary conversion unit on a primary side of the transformer; a secondary conversion unit on a secondary side; a primary bypass device for short-circuiting between input terminals of the cell; and a secondary bypass device for short-circuiting between output terminals of the cell. The input terminals and/or the output terminals of the cells are connected in series. When the primary conversion unit(s) of a part of the cells is stopped, the controller turns on the primary bypass device and sets secondary DC link voltages to prescribed values; and when the secondary conversion unit(s) of a part of the cells is stopped, the controller turns on the secondary bypass device and controls the primary conversions units to set primary DC link voltages to prescribed values.

Abstract: A power conversion device that suppresses voltage pulsation of a capacitor of a power converter with respect to a control target whose effective power is to be controlled is provided. The power conversion device includes a plurality of power conversion cells that are connected to each other, and convert a primary-side system voltage into a secondary-side system voltage, a capacitor that is connected to each of the plurality of power conversion cells, and a power conversion cell driver that drives the power conversion cells to add a 3N order higher-harmonic-wave voltage of each of alternating voltages of the plurality of power conversion cells to the each of alternating voltages, and output a voltage made by adding the each of alternating voltages and the 3N order higher-harmonic-wave voltage, when N is a natural number.

Abstract: A power conversion device includes three first power conversion cells each converting input power and outputting the converted power and having input terminals connected in parallel regarding a first power supply and three second power conversion cells each converting input power and outputting the converted power and having input terminals connected in parallel regarding a second power supply, wherein: the power output from the cell and the power output from the cell are combined to output a first phase power; the power output from the cell and the power output from the cell are combined to output a second phase power; and the power output from the cell and the power output from the cell are combined to output a third phase power. The first phase, second phase, and third phase powers are output as the phase powers or inter-line powers of a three-phase system.

Abstract: A power conversion device includes: a first low voltage side circuit and a first high voltage side circuit which are connected via a first transformer; and a second low voltage side circuit and a second high voltage side circuit which are connected via a second transformer, wherein switching timings of the first high voltage side circuit and the second high voltage side circuit are controlled such that a current difference of an input current to the first low voltage side circuit and an input current to the second low voltage side circuit during a step-up operation becomes smaller than a predetermined value. A driver circuit to output a drive signal of a switching element may be included in at least one of the first low voltage side circuit and the second low voltage side circuit.

Abstract: An object of the present invention is to provide a highly efficient power supply device. A power supply device 1 according to the present invention includes a bidirectional DC-DC converter 3 and an insulated DC-DC converter 4. The bidirectional DC-DC converter 3 receives a main battery 5 and outputs a direct-current link voltage Vlink. The insulated DC-DC converter 4 receives the link voltage Vlink and supplies power to a load 7. The link voltage Vlink, which is an output of the bidirectional DC-DC converter 3, changes according to the output voltage of the insulated DC-DC converter 4.

Abstract: In a power conversion device, a power conversion unit includes a single-phase inverter on a secondary side of a resonant type converter that has an input of a direct current. A power conversion unit group is configured by connecting outputs of the single-phase inverters of a plurality of power conversion units in series. Respective phases of three phase alternate current are formed with the three power conversion unit groups housed in a power conversion device housing. The plurality of power conversion units constituting the power conversion unit group are disposed along a longitudinal direction of the power conversion device housing. The respective three power conversion unit groups are disposed at an upper stage, a middle stage, and a lower stage in a height direction of the power conversion device housing. The power conversion device housing has one end side in the longitudinal direction as output terminals of the three power conversion unit groups.

Abstract: A power conversion device includes: power conversion cells; and a controller to control the cells. Each cell includes: a transformer; a primary conversion unit on a primary side of the transformer; a secondary conversion unit on a secondary side; a primary bypass device for short-circuiting between input terminals of the cell; and a secondary bypass device for short-circuiting between output terminals of the cell. The input terminals and/or the output terminals of the cells are connected in series. When the primary conversion unit(s) of a part of the cells is stopped, the controller turns on the primary bypass device and sets secondary DC link voltages to prescribed values; and when the secondary conversion unit(s) of a part of the cells is stopped, the controller turns on the secondary bypass device and controls the primary conversions units to set primary DC link voltages to prescribed values.

Abstract: An object of the present invention is to provide a charging apparatus having high efficiency of charging a battery by inputting an alternating current voltage. A charging apparatus that charges a direct current battery includes a step-down converter unit to which a direct current voltage from a power supply is input and that converts the direct current voltage, and when a voltage of the direct current battery is between a predetermined first voltage smaller than a charge completion voltage of the direct current battery and the charge completion voltage, a variable voltage that increases from the first voltage to the charge completion voltage in accordance with charging of the direct current battery is input to the step-down converter unit.

Abstract: In a power conversion device in a configuration in which a plurality of power converter cells has serially connected outputs and includes a converter and an inverter as components, when a load is light, the cells also operate with a light load, and efficiency is reduced. A power conversion device has a plurality of power converter cells. The outputs of the cells are connected in series. The device has a controller that controls the cells. The cells each have a converter that converts an externally inputted power supply voltage and generates a DC link voltage and an inverter that converts the DC link voltage into an alternating current voltage and outputs the current. The controller stops a converter in some of the cells depending on power supply electric power or load electric power. The inverter continues to operate using a link capacitor as a power supply.

Abstract: Provided is a power source device having a high efficiency. A power source device 1 includes an insulated AC-DC converter 2 which receives a voltage of an AC power source 10 and outputs a link voltage Vlink, a bidirectional DC-DC converter 3 which receives the link voltage Vlink to charge a main battery 5, an insulated DC-DC converter 4 which receives the link voltage Vlink to supply power to a load 7, an operation mode in which the power is supplied from the AC power source 10 to the main battery 5, and an operation mode in which the power is supplied from the main battery 5 to the load 7.