Abstract: The present DC power supply and distribution system includes a plurality of distribution lines provided respectively corresponding to a plurality of loads, a first converter to convert an AC voltage from a commercial AC power source into a plurality of DC voltages and supply the DC voltages respectively to the distribution lines, a second converter to convert a DC power from a power generation and storage source into a plurality of DC powers and supply the DC powers respectively to the distribution lines, and a power controller to control the DC powers such that the efficiency of the first converter is increased, based on information related to the efficiency of the second converter.

Abstract: A power supply system includes a power converter, a load state detector, and a controller. The power converter converts AC power received from the main power source into DC power with a voltage in accordance with a distribution voltage command value Vref and supplies the DC power to the load. The load state detector detects an operating state of the load. The controller operates in an operation mode selected from among a plurality of operation modes and generates the distribution voltage command value Vref. The operation modes include a distribution voltage control mode in which the distribution voltage command value Vref is generated based on load operating information detected by the load state detector and a distribution voltage fixed mode in which a predetermined setting value or an external command value acquired from an external device is set as the distribution voltage command value Vref.

Abstract: The present disclosure includes: a power generator; and a power line through which power generated by the power generator is transmitted to a load. The power line between the power generator and the load is provided with: a current limitation device configured to, when detecting occurrence of a fault current, limit the fault current; and a current interruption device configured to interrupt current heading for the load, in conjunction with the limitation of the fault current performed by the current limitation device.

Abstract: An object is to obtain a power conversion device that can stabilize output voltage to a DC load. A power conversion device includes an AC/DC conversion unit having a power conversion circuit composed of a plurality of first semiconductor switching elements connected in a full-bridge form, and a full-bridge chopper circuit unit having a full-bridge chopper circuit composed of a plurality of second semiconductor switching elements connected in a full-bridge form, and connected to a positive terminal and a negative terminal. A neutral point of an AC filter capacitor unit and a neutral point of a DC filter capacitor unit are connected via a neutral point line.

Abstract: The semiconductor circuit breaker includes a semiconductor switch unit connected to an AC circuit, and a phase control unit that controls conduction and non-conduction of the semiconductor switch unit by the control signal. The phase control unit includes an accident detection unit to detect an accident based on a current detected from the AC circuit, a zero point detection unit to detect a current zero point based on the current detected from the AC circuit, and a control signal output unit to output the control signal for setting the semiconductor switch unit to be non-conductive when the accident detection unit detects the accident or when the zero point detection unit detects the current zero point in response to a command to cut off the current.

Abstract: A power conversion device includes an AC/DC conversion unit, at least one DC/DC conversion unit connected in parallel to a DC output of the AC/DC conversion unit, and a control unit for controlling the AC/DC conversion unit and the DC/DC conversion unit, wherein at least one of two or more DC outputs is the DC output of the AC/DC conversion unit and the DC/DC conversion unit includes two chopper legs.

Abstract: The present DC power supply and distribution system comprises: a plurality of power distribution lines each connected to a respective one of a plurality of loads; a first converter to receive an AC voltage from a commercial AC power source, convert the received AC voltage into a plurality of DC voltages and supply each of the plurality of DC voltages to a respective one of the plurality of power distribution lines; a second converter to receive a DC power from a power generating and/or storing source, convert the received DC power into a plurality of DC powers, and supply each of the plurality of DC powers to a respective one of the plurality of power distribution lines; and a controller to enhance the second converter in efficiency by controlling the first converter so that a ratio of the plurality of DC voltages is a predetermined first ratio.

Abstract: The present disclosure includes: a power generator; and a power line through which power generated by the power generator is transmitted to a load. The power line between the power generator and the load is provided with: a current limitation device configured to, when detecting occurrence of a fault current, limit the fault current; and a current interruption device configured to interrupt current heading for the load, in conjunction with the limitation of the fault current performed by the current limitation device.

Abstract: An object is to obtain a power conversion device that can stabilize output voltage to a DC load. A power conversion device includes an AC/DC conversion unit having a power conversion circuit composed of a plurality of first semiconductor switching elements connected in a fill-bridge form, and a full-bridge chopper circuit unit having a full-bridge chopper circuit composed of a plurality of second semiconductor switching elements connected in a full-bridge form, and connected to a positive terminal and a negative terminal. A neutral point of an AC filter capacitor unit and a neutral point of a DC filter capacitor unit are connected via a neutral point line.

Abstract: A power supply system includes a power converter, a load state detector, and a controller. The power converter converts AC power received from the main power source into DC power with a voltage in accordance with a distribution voltage command value Vref and supplies the DC power to the load. The load state detector detects an operating state of the load. The controller operates in an operation mode selected from among a plurality of operation modes and generates the distribution voltage command value Vref. The operation modes include a distribution voltage control mode in which the distribution voltage command value Vref is generated based on load operating information detected by the load state detector and a distribution voltage fixed mode in which a predetermined setting value or an external command value acquired from an external device is set as the distribution voltage command value Vref.

Abstract: A DC supply and distribution system includes an AC-DC converter for converting an AC power input from an AC power line to DC powers having a plurality of different voltages and outputting the converted DC powers; and a voltage controller for controlling the different voltages of the DC powers to be output from the AC-DC converter. The output DC powers are distributed to the plurality of loads through a plurality of respective DC lines connected from the output terminals of the AC-DC converter.

Abstract: The present DC power supply and distribution system includes a plurality of distribution lines provided respectively corresponding to a plurality of loads, a first converter to convert an AC voltage from a commercial AC power source into a plurality of DC voltages and supply the DC voltages respectively to the distribution lines, a second converter to convert a DC power from a power generation and storage source into a plurality of DC powers and supply the DC powers respectively to the distribution lines, and a power controller to control the DC powers such that the efficiency of the first converter is increased, based on information related to the efficiency of the second converter.

Abstract: A DC supply and distribution system includes an AC-DC converter for converting an AC power input from an AC power line to DC powers having a plurality of different voltages and outputting the converted DC powers; and a voltage controller for controlling the different voltages of the DC powers to be output from the AC-DC converter. The output DC powers are distributed to the plurality of loads through a plurality of respective DC lines connected from the output terminals of the AC-DC converter.

Abstract: The semiconductor circuit breaker includes a semiconductor switch unit connected to an AC circuit, and a phase control unit that controls conduction and non-conduction of the semiconductor switch unit by the control signal. The phase control unit includes an accident detection unit to detect an accident based on a current detected from the AC circuit, a zero point detection unit to detect a current zero point based on the current detected from the AC circuit, and a control signal output unit to output the control signal for setting the semiconductor switch unit to be non-conductive when the accident detection unit detects the accident or when the zero point detection unit detects the current zero point in response to a command to cut off the current.

Abstract: A filter device that removes a noise current generated by an inverter includes a first filter capacitor that is provided in parallel to a direct-current unit of the inverter, a first filter reactor that is provided between a high-potential side of the first filter capacitor and an overhead line that is a power supply source of direct-current power, and a series circuit unit in which a fuse serving as a circuit disconnecting unit that is disconnected when a current larger than a rated current flows therein, a second filter reactor serving as an inductance element, and a second filter capacitor serving as a capacitance element are connected in series, where one end of the series circuit unit is connected to a low-potential side of the first filter capacitor and one end of the first filter reactor is connected to the series circuit unit.

Abstract: A filter device that removes a noise current generated by an inverter includes a first filter capacitor that is provided in parallel to a direct-current unit of the inverter, a first filter reactor that is provided between a high-potential side of the first filter capacitor and an overhead line that is a power supply source of direct-current power, and a series circuit unit in which a fuse serving as a circuit disconnecting unit that is disconnected when a current larger than a rated current flows therein, a second filter reactor serving as an inductance element, and a second filter capacitor serving as a capacitance element are connected in series, where one end of the series circuit unit is connected to a low-potential side of the first filter capacitor and one end of the first filter reactor is connected to the series circuit unit.

Abstract: To realize a transmission function of power line communication by a further simplified and cost-effective circuit configuration, in a PLC modem installed in an electric appliance such as a household electrical appliance. A semiconductor switching element that is present on an electric circuit connected to a power line is driven by a modulator unit. The modulator unit controls ON/OFF operations of the semiconductor switching element, to thereby cause a communication signal of a modulated rectangular wave to be output to the power line for a prescribed period.

Abstract: To realize a transmission function of power line communication by a further simplified and cost-effective circuit configuration, in a PLC modem installed in an electric appliance such as a household electrical appliance. A semiconductor switching element that is present on an electric circuit connected to a power line is driven by a modulator unit. The modulator unit controls ON/OFF operations of the semiconductor switching element, to thereby cause a communication signal of a modulated rectangular wave to be output to the power line for a prescribed period.