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: 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: Provided is a power conversion device by which an inverter MOS transistors included in an inverter can be prevented from short-circuiting. It has a DC/DC converter unit converting a voltage of DC power to be inputted, a transformation unit transforming the DC power converted by the DC/DC converter unit, an inverter unit converting the DC power transformed by the transformation unit to AC power, a control unit driving/controlling the inverter unit, a wireless power reception unit receiving power fed by wireless power feed to supply it to the control unit, a wireless power transmission unit transmitting power to the wireless power reception unit, and a power supply unit supplying power to the wireless power transmission unit.

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: 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: 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: 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: 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: 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: Provided is a power conversion device by which an inverter MOS transistors included in an inverter can be prevented from short-circuiting. It has a DC/DC converter unit converting a voltage of DC power to be inputted, a transformation unit transforming the DC power converted by the DC/DC converter unit, an inverter unit converting the DC power transformed by the transformation unit to AC power, a control unit driving/controlling the inverter unit, a wireless power reception unit receiving power fed by wireless power feed to supply it to the control unit, a wireless power transmission unit transmitting power to the wireless power reception unit, and a power supply unit supplying power to the wireless power transmission unit.

Abstract: If an input voltage of a DC/DC converter is lower than a first voltage value that is set in advance, a converter controller maintains an output voltage of the DC/DC converter within a first voltage range that is set in advance by changing an operation frequency of switching of the DC/DC converter in compliance with the input voltage as a first voltage maintaining control. If the input voltage is higher than a second voltage value that is higher than the first voltage value, the converter controller maintains the output voltage within a second voltage range that is higher than the first voltage range by changing the operation frequency in compliance with the input voltage as a second voltage maintaining control.

Abstract: Reduction in size and weight of transformer for grid tie applications is demanded and can be achieved by applying SST to the transformer. However, SST application to PCS for sunlight requires the following: handle a wide variation range of the voltage of solar power generation; reduce switching losses of power devices, DC/DC converter and inverter, in the power circuit to implement high frequency for SST application; increase voltage to the grid voltage; and reduce the dimensions of the high current path prior to step-up. Thus, LLC resonant converter configuration is applied with an inverter placed in the output, and series connected configuration is applied to the inverter. The LLC resonant converter is subject to constant frequency regulation with large output, step-up control with low output, and step-down control with the upper limit voltage according to MPPT voltage from sunlight, in order to achieve drive loss reduction and voltage range handling.

Abstract: Size and weight reduction of a transformer for system interconnection is needed. Applying an SST to the transformer can reduce the size and weight. However, it is also necessary to flexibly handle a wide range of voltages to match a high-voltage system or motor, reduce switching loss of a power device used in a power circuit such as a DC/DC converter and an inverter in association with frequency increase caused by application of the SST, and achieve size reduction of a cooling structure. Further, it is necessary to boost a voltage to a system voltage and reduce the size and weight of a large current path before the voltage boosting. Thus, an LLC resonant converter structure is applied, and a multiple-connection structure is employed in each of which a converter is arranged for an input or an inverter is arranged for an output. This enables handling of various voltage ranges by various combinations of the numbers of multiple connections of the inputs and the outputs.

Abstract: In order to reduce the size of an isolation transformer, the present invention provides a power conversion device including: a first inverter unit for obtaining a DC input and giving a high frequency output; an LLC transformer for converting the voltage of the high frequency output of the first inverter unit; a rectifier unit for DC-converting the voltage of the output of the LLC transformer; a second inverter unit for converting the DC output of the rectifier unit into AC; and a control circuit for obtaining the gate power of a semiconductor device configuring the second inverter unit through a power supply transformer for the control circuit that is connected in parallel to the secondary circuit of the LLC transformer.

Abstract: Size and weight reduction of a transformer for system interconnection is needed. Applying an SST to the transformer can reduce the size and weight. However, it is also necessary to flexibly handle a wide range of voltages to match a high-voltage system or motor, reduce switching loss of a power device used in a power circuit such as a DC/DC converter and an inverter in association with frequency increase caused by application of the SST, and achieve size reduction of a cooling structure. Further, it is necessary to boost a voltage to a system voltage and reduce the size and weight of a large current path before the voltage boosting. Thus, an LLC resonant converter structure is applied, and a multiple-connection structure is employed in each of which a converter is arranged for an input or an inverter is arranged for an output. This enables handling of various voltage ranges by various combinations of the numbers of multiple connections of the inputs and the outputs.

Abstract: Reduction in size and weight of transformer for grid tie applications is demanded and can be achieved by applying SST to the transformer. However, SST application to PCS for sunlight requires the following: handle a wide variation range of the voltage of solar power generation; reduce switching losses of power devices, DC/DC converter and inverter, in the power circuit to implement high frequency for SST application; increase voltage to the grid voltage; and reduce the dimensions of the high current path prior to step-up. Thus, LLC resonant converter configuration is applied with an inverter placed in the output, and series connected configuration is applied to the inverter. The LLC resonant converter is subject to constant frequency regulation with large output, step-up control with low output, and step-down control with the upper limit voltage according to MPPT voltage from sunlight, in order to achieve drive loss reduction and voltage range handling.

Abstract: If an input voltage of a DC/DC converter is lower than a first voltage value that is set in advance, a converter controller maintains an output voltage of the DC/DC converter within a first voltage range that is set in advance by changing an operation frequency of switching of the DC/DC converter in compliance with the input voltage as a first voltage maintaining control. If the input voltage is higher than a second voltage value that is higher than the first voltage value, the converter controller maintains the output voltage within a second voltage range that is higher than the first voltage range by changing the operation frequency in compliance with the input voltage as a second voltage maintaining control.

Abstract: A power supply device according to the present invention includes: a capacitor 10 connected in parallel with a battery; two switching circuits 31,32 connected in series with the capacitor 10; a pre-charge switching circuit 33 connected in parallel with one of the two switching circuits 31,32; and a control unit 14 that, when a voltage of the capacitor 10 is lower than a voltage of the battery 1, controls the pre-charge switching circuit 33 and the switching circuit 32 and performs pre-charging current limitation for the capacitor 10.

Abstract: A power supply device according to the present invention includes: a capacitor 10 connected in parallel with a battery; two switching circuits 31,32 connected in series with the capacitor 10; a pre-charge switching circuit 33 connected in parallel with one of the two switching circuits 31,32; and a control unit 14 that, when a voltage of the capacitor 10 is lower than a voltage of the battery 1, controls the pre-charge switching circuit 33 and the switching circuit 32 and performs pre-charging current limitation for the capacitor 10.

Abstract: Fuel concentration near a power generator of a DMFC is adjusted by decreasing current taken from the DMFC when the concentration near the power generator of the DMFC is higher than an optimum value and increasing the current taken from the DMFC when the concentration near the power generator of the DMFC is lower than the optimum value. Since the fuel does not come into direct contact with the power generator in the DMFC in a portion from a cartridge to the power generator in the DMFC, drying of the fuel is suppressed. By providing an auxiliary tank capable of storing fuel, concentration of methanol supplied near the power generator of the DMFC is lowered upon activation after long-time storage.