Abstract: In an electric power conversion device according to an embodiment, a chopper converts electric power from a power supply into direct-current power. An inverter converts the direct-current power into alternating-current power. Pairs of resonant capacitors are connected to a direct-current input section of the inverter. Each of the pairs is in series. Primary windings of high-frequency transformers are connected to the inverter and respective midpoints of the pairs of resonant capacitors. The high-frequency transformers convert the alternating-current power of the inverter. Rectifiers convert alternating-current power supplied from secondary windings of the high-frequency transformers into direct-current power. One or more voltage detectors detect output voltage of one or more of the rectifiers. A control device controls the chopper on the basis of output of the voltage detectors such that an output voltage of the direct-current power comes to a predetermined voltage value.

Abstract: A resonant inverter of a power supply for electric vehicle includes a first resonant capacitor and a switching element cutting off a current flowing in a resonant circuit and generates first alternating-current power from direct-current power. The transformer is included in a part of the resonant circuit, supplies the first alternating-current power generated by the resonant inverter to a first winding, and supplies second alternating-current power after conversion of the first alternating-current power to a load from a second winding. A control unit confines a difference between a resonant frequency of the resonant circuit and a switching frequency of the switching element to a predetermined range to cause that a current flowing in switching of the switching element to at least the first winding or the second winding is equal to or less than a predetermined value and to cause the resonant inverter to perform soft switching.

Abstract: A resonant inverter of a power supply for electric vehicle includes a first resonant capacitor and a switching element cutting off a current flowing in a resonant circuit and generates first alternating-current power from direct-current power. The transformer is included in a part of the resonant circuit, supplies the first alternating-current power generated by the resonant inverter to a first winding, and supplies second alternating-current power after conversion of the first alternating-current power to a load from a second winding. A control unit confines a difference between a resonant frequency of the resonant circuit and a switching frequency of the switching element to a predetermined range to cause that a current flowing in switching of the switching element to at least the first winding or the second winding is equal to or less than a predetermined value and to cause the resonant inverter to perform soft switching.

Abstract: A power conversion system includes a transformer, a power conversion device for travel, a power conversion device for auxiliary power sources, an electrical storage device, and an auxiliary device. The power conversion device for travel converts AC power into power for travel and supplies it to a travel motor. The power conversion device for auxiliary power sources includes an AC to DC conversion unit which converts AC power into DC power, a power conversion unit for AC loads which converts the DC power into AC power and supplies it to an AC load, and a power conversion unit for DC loads which converts DC power to DC power and supplies it to a DC load. The electrical storage device is connected to power lines connecting DC power output terminals of the AC to DC conversion unit and DC power input terminals of both the power conversion units for AC and DC loads.

Abstract: A power conversion system includes an AC to DC conversion circuit, a voltage detector, a step-down chopper circuit, a power conversion device for auxiliary power sources, and a control unit. The AC to DC conversion circuit converts AC power supplied from overhead wires via a transformer into DC power. The voltage detector detects a voltage of AC power supplied from the transformer. The step-down chopper circuit steps down the voltage of DC power produced through conversion by the AC to DC conversion circuit. The power conversion device for auxiliary power sources converts the DC power stepped down by the step-down chopper circuit into power for driving loads mounted in an electric vehicle and supplies it to the loads. The control unit controls the AC to DC conversion circuit and the step-down chopper circuit such that the voltage of AC power detected by the voltage detector approaches a reference voltage.

Abstract: A power conversion system includes a transformer, a power conversion device for travel, a power conversion device for auxiliary power sources, and an electrical storage device. The power conversion device for auxiliary power sources includes a first AC to DC conversion unit, a power conversion unit for AC loads, and a power conversion unit for DC loads. The power conversion unit for AC loads converts DC power into AC power and supplies it to an AC load. The power conversion unit for DC loads converts DC power produced through conversion by the first AC to DC conversion unit into DC power and supplies it to a DC load. The electrical storage device is connected to power lines connecting DC power output terminals of the first AC to DC conversion unit and DC power input terminals of both the power conversion units for AC and DC loads.

Abstract: A power conversion system includes a transformer, a power conversion device for travel, a power conversion device for auxiliary power sources, and an electrical storage device. The power conversion device for auxiliary power sources includes a first AC to DC conversion unit, a power conversion unit for AC loads, and a power conversion unit for DC loads. The power conversion unit for AC loads converts DC power into AC power and supplies it to an AC load. The power conversion unit for DC loads converts DC power produced through conversion by the first AC to DC conversion unit into DC power and supplies it to a DC load. The electrical storage device is connected to power lines connecting DC power output terminals of the first AC to DC conversion unit and DC power input terminals of both the power conversion units for AC and DC loads.

Abstract: A power conversion system includes a transformer, a power conversion device for travel, a power conversion device for auxiliary power sources, an electrical storage device, and an auxiliary device. The power conversion device for travel converts AC power into power for travel and supplies it to a travel motor. The power conversion device for auxiliary power sources includes an AC to DC conversion unit which converts AC power into DC power, a power conversion unit for AC loads which converts the DC power into AC power and supplies it to an AC load, and a power conversion unit for DC loads which converts DC power to DC power and supplies it to a DC load. The electrical storage device is connected to power lines connecting DC power output terminals of the AC to DC conversion unit and DC power input terminals of both the power conversion units for AC and DC loads.

Abstract: A power conversion system includes an AC to DC conversion circuit, a voltage detector, a step-down chopper circuit, a power conversion device for auxiliary power sources, and a control unit. The AC to DC conversion circuit converts AC power supplied from overhead wires via a transformer into DC power. The voltage detector detects a voltage of AC power supplied from the transformer. The step-down chopper circuit steps down the voltage of DC power produced through conversion by the AC to DC conversion circuit. The power conversion device for auxiliary power sources converts the DC power stepped down by the step-down chopper circuit into power for driving loads mounted in an electric vehicle and supplies it to the loads. The control unit controls the AC to DC conversion circuit and the step-down chopper circuit such that the voltage of AC power detected by the voltage detector approaches a reference voltage.

Abstract: A vehicle control device for a first railroad vehicle includes a case, a first wireless router device housed in the case, and an antenna device. The antenna device is installed on any of outer peripheral surfaces of the case. The first wireless router device transmits collected operation data of the vehicle control device via the antenna device and a first wireless communication network to a second wireless router device arranged in a second railroad vehicle so that a gateway router also arranged in the second railroad vehicle can transmit the collected operation data to an external server via a second wireless communication network.