Abstract: In first power transmission in which power is transmitted from a first DC power source to a second DC power source, a control circuit performs on/off drive control of a positive electrode-side switching element and a negative electrode-side switching element in a first bridge circuit and a second bridge circuit and stops on/off drive of a positive electrode-side switching element and a negative electrode-side switching element in a third bridge. For a positive electrode-side switching element and a negative electrode-side switching element of a fourth bridge circuit, when a first power transmission amount by the first power transmission is greater than a predetermined first reference value, the control circuit performs on/off drive control, whereas when the first power transmission amount is smaller than the first reference value, the control circuit stops on/off drive.

Abstract: In a DC/DC converter, in first power transmission in which power is transmitted from a first DC power source to a second DC power source, on/off drive of a positive electrode-side switching element and a negative electrode-side switching element is stopped in a third bridge circuit on the power-receiving side. When a power transmission amount by the first power transmission is smaller than a first reference value, a control circuit lowers the switching frequency of the switching elements of a first bridge circuit and a second bridge circuit on the power-transmitting side and a fourth bridge circuit on the power-receiving side, compared with when the power transmission amount is equal to or greater than the first reference value.

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: A power supply system includes a plurality of power conversion devices connected in parallel with each other, a load state detector to detect an operating state of a load connected to the DC system, and a command generator to generate a distribution voltage command Vref Each of the power conversion devices includes a DC voltage controller to generate an output power command Pdc_ref based on a voltage of the DC system and the distribution voltage command Vref, and an AC/DC converter to convert AC power received from the main power source based on the output power command Pdc_ref and output the converted power to the DC system. The command generator generates the distribution voltage command Vref such that loss of the load connected to the DC system is reduced, based on a detection result of the load state detector.

Abstract: An output terminal of a contact type charger connected to an AC power supply 1 and being for boosting or stepping down an input voltage, and an output terminal of a non-contact type charger for receiving power in a non-contact manner are connected to an input terminal of a DC/DC converter via an integrated bus, a DC link capacitor is connected between an AC/DC converter and an isolated DC/DC converter included in the contact type charger, an integrated capacitor is connected to the integrated bus, and a control circuit adjusts a DC voltage of the DC link capacitor or the integrated capacitor such that at least one of power losses or a total power loss of the contact type charger, the non-contact type charger, and the DC/DC converter is reduced.

Abstract: In a DC/DC converter, in first power transmission in which power is transmitted from a first DC power source to a second DC power source, on/off drive of a positive electrode-side switching element and a negative electrode-side switching element is stopped in a third bridge circuit on the power-receiving side. When a power transmission amount by the first power transmission is smaller than a first reference value, a control circuit lowers the switching frequency of the switching elements of a first bridge circuit and a second bridge circuit on the power-transmitting side and a fourth bridge circuit on the power-receiving side, compared with when the power transmission amount is equal to or greater than the first reference value.

Abstract: In first power transmission in which power is transmitted from a first DC power source to a second DC power source, a control circuit performs on/off drive control of a positive electrode-side switching element and a negative electrode-side switching element in a first bridge circuit and a second bridge circuit and stops on/off drive of a positive electrode-side switching element and a negative electrode-side switching element in a third bridge. For a positive electrode-side switching element and a negative electrode-side switching element of a fourth bridge circuit, when a first power transmission amount by the first power transmission is greater than a predetermined first reference value, the control circuit performs on/off drive control, whereas when the first power transmission amount is smaller than the first reference value, the control circuit stops on/off drive.

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: A parallel power supply device according to the present invention includes: a plurality of DC/DC converters connected in parallel to perform power conversion between a DC power supply and a common load; a voltage detector to detect a voltage of the common load; and a plurality of control circuits each to control a corresponding one of the plurality of DC/DC converters, wherein during parallel operation of the plurality of DC/DC converters, the plurality of control circuits control the plurality of DC/DC converters by proportional control using a same target voltage value and a same proportional gain, based on a voltage value of the common load detected by the voltage detector. Therefore, in the parallel power supply device in which the plurality of DC/DC converters are connected in parallel, the individual DC/DC converters can supply electric power to the load independently and equally.

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: An output terminal of a contact type charger connected to an AC power supply 1 and being for boosting or stepping down an input voltage, and an output terminal of a non-contact type charger for receiving power in a non-contact manner are connected to an input terminal of a DC/DC converter via an integrated bus, a DC link capacitor is connected between an AC/DC converter and an isolated DC/DC converter included in the contact type charger, an integrated capacitor is connected to the integrated bus, and a control circuit adjusts a DC voltage of the DC link capacitor or the integrated capacitor such that at least one of power losses or a total power loss of the contact type charger, the non-contact type charger, and the DC/DC converter is reduced.

Abstract: A parallel power supply device according to the present invention includes: a plurality of DC/DC converters connected in parallel to perform power conversion between a DC power supply and a common load; a voltage detector to detect a voltage of the common load; and a plurality of control circuits each to control a corresponding one of the plurality of DC/DC converters, wherein during parallel operation of the plurality of DC/DC converters, the plurality of control circuits control the plurality of DC/DC converters by proportional control using a same target voltage value and a same proportional gain, based on a voltage value of the common load detected by the voltage detector. Therefore, in the parallel power supply device in which the plurality of DC/DC converters are connected in parallel, the individual DC/DC converters can supply electric power to the load independently and equally.

Abstract: A parallel power supply device includes a plurality of DC/DC converters connected in parallel, and each DC/DC converter includes: first and second switching circuits with a transformer therebetween; first and second reactors; and a control circuit. The control circuit generates a duty cycle so that a deviation between voltage of a load and target voltage becomes 0. Correction is performed such that, when the magnitude of the duty cycle is smaller than a set value Vth, the magnitude is fixed at 0, and otherwise, the magnitude is decreased by the set value Vth. Then, the phase shift amounts for drive signals for the first and second switching circuits are determined, and the first and second switching circuits are subjected to phase shift control.

Abstract: A DC/DC converter enabling a step-up operation and a step-down operation in a bidirectional power transmission, and capable of adjusting transmission power amount with a good response. A DC/DC converter decreases a first phase shift amount and increases a second phase shift amount, as a first transmission power amount increases, when a first transmission power amount is larger than a first reference point.

Abstract: A temperature estimation device calculates a first estimation temperature of a reactor on the basis of a reference estimation temperature to which a first lag period is provided and outputs from a temperature change amount calculation unit to which a second lag period is provided, predicts a second temperature change amount of the reactor over a predetermined period on the basis of the first estimation temperature, and then predicts a second estimation temperature of the reactor.

Abstract: A temperature estimation device calculates a first estimation temperature of a reactor on the basis of a reference estimation temperature to which a first lag period is provided and outputs from a temperature change amount calculation unit to which a second lag period is provided, predicts a second temperature change amount of the reactor over a predetermined period on the basis of the first estimation temperature, and then predicts a second estimation temperature of the reactor.

Abstract: A DC/DC converter enabling a step-up operation and a step-down operation in a bidirectional power transmission, and capable of adjusting transmission power amount with a good response. A DC/DC converter decreases a first phase shift amount and increases a second phase shift amount, as a first transmission power amount increases, when a first transmission power amount is larger than a first reference point.

Abstract: A first DC/DC converter is of a constant voltage control type and is controlled so as to keep the voltage of an electric generation bus at a predetermined target value. A second DC/DC converter is of a constant current control type and is controlled so as to keep input current or output current at predetermined target current. A control circuit determines an optimum target value of electric generation bus voltage, based on different algorithms, in accordance with all or some of modes A to C which are classified by the charging/discharging condition of a second electric storage device, and controls the first DC/DC converter so that the electric generation bus voltage becomes the determined target value.