Abstract: An electric power conversion apparatus according the present disclosure includes: voltage detection means which detects the voltages of both bridge circuits, and a control device which controls the semiconductor switching elements of both bridge circuits. The control device includes a phase difference operation part which calculates a phase difference between the output of the first bridge circuit and the output of the second bridge circuit, based on the voltage values of both bridge circuits which are detected by the voltage detection means and an electric power command value; a compensation amount operation part which calculates a compensation amount which compensates an error due to the phase difference; and a PWM signal generation part which generates gate signals of the semiconductor switching elements, from a first operation result of the phase difference operation part and a second operation result of the compensation amount operation part.

Abstract: A DC power distribution system includes: a transformer; a rectification device; a DC bus through which DC power flows; a plurality of DC branch lines branching off from the DC bus; an AC interrupting portion connected to an input side of the transformer; a first DC interrupting portion connected between the rectification device and the DC bus; and a plurality of second DC interrupting portions respectively provided to the plurality of DC branch lines. An interrupting-operation time for each second DC interrupting portion is set to be shorter than interrupting-operation times for the AC interrupting portion and the first DC interrupting portion. An inductance value of a short-circuit impedance of the transformer is set to a value at which short-circuit current can be limited to take a value not larger than a maximum current value permitted for the rectification device.

Abstract: The present disclosure suppresses increase in device cost in a DC power distribution system that can disconnect a distribution line on which a short-circuit failure has occurred, from an output path. This DC power distribution system includes: a plurality of power conversion devices; one DC busbar; a plurality of distribution lines; a plurality of first current interruption portions respectively connected to input sides of the power conversion devices; a plurality of second current interruption portions connected between the power conversion devices and the DC busbar; and a plurality of third current interruption portions respectively provided on the distribution lines. Interruption current values of the third current interruption portions are set to smaller values than a maximum allowable current value of the power conversion device in which short-circuit current will reach the maximum allowable current value in a shortest time.

Abstract: In the conventional elimination of a short-circuited point by using fuses, due to the fuse characteristics, it is not possible to ensure cooperation at the respective melting times of fuses in a short-circuit state. To solve such a problem, provided are a converter which limits a current passing through a distribution line in a short-circuit state and has a constant power drooping characteristic of passing a current greater than or equal to a rated current through the distribution line for a fixed time, and relays which have an operating characteristic of detecting a current greater than or equal to the rated current and hierarchically opening switches within the fixed time.

Abstract: A DC power distribution system includes: a transformer; a rectification device; a DC bus through which DC power flows; a plurality of DC branch lines branching off from the DC bus; an AC interrupting portion connected to an input side of the transformer; a first DC interrupting portion connected between the rectification device and the DC bus; and a plurality of second DC interrupting portions respectively provided to the plurality of DC branch lines. An interrupting-operation time for each second DC interrupting portion is set to be shorter than interrupting-operation times for the AC interrupting portion and the first DC interrupting portion. An inductance value of a short-circuit impedance of the transformer is set to a value at which short-circuit current can be limited to take a value not larger than a maximum current value permitted for the rectification device.

Abstract: An object is to provide a DC distribution panel that, even when short-circuit current has occurred in one feeder, interrupts only the feeder where short-circuit current has occurred, and thus can continue operations of load apparatuses connected to normal feeders. This DC distribution panel includes: an input terminal including positive and negative input terminals; circuit breakers having short-circuit current interruption units connected to at least either of positive electric paths and negative electric paths respectively branched from the positive and negative input terminals; and output terminals including positive output terminals and negative output terminals of the plurality of circuit breakers. At least one of the plurality of circuit breakers includes a reverse current interruption unit for interrupting reverse current flowing through the positive electric path from the output terminal side to the input terminal side.

Abstract: In the conventional elimination of a short-circuited point by using fuses, due to the fuse characteristics, it is not possible to ensure cooperation at the respective melting times of fuses in a short-circuit state. To solve such a problem, provided are a converter which limits a current passing through a distribution line in a short-circuit state and has a constant power drooping characteristic of passing a current greater than or equal to a rated current through the distribution line for a fixed time, and relays which have an operating characteristic of detecting a current greater than or equal to the rated current and hierarchically opening switches within the fixed time.