Abstract: An electric power conversion system includes: a primary electric power conversion circuit including primary right and left arms; a secondary electric power conversion circuit including secondary right and left arms; and a control circuit controlling transfer of electric power between the primary and secondary electric power conversion circuits by magnetically coupling a primary coil to a secondary coil. The control circuit sets an interphase difference in switching between right and left arm lower transistors in the primary electric power conversion circuit and an interphase difference in switching between right and left arm lower transistors in the secondary electric power conversion circuit on the basis of off times of the primary and secondary electric power conversion circuits such that a phase difference between terminal voltage waveforms of the primary and secondary coils is 0 and duty ratios of the terminal voltage waveforms are equal to each other.

Abstract: A power supply system includes a plurality of power supply circuits connected to a common output node and a control unit that controls outputs of the plurality of power supply circuits such that an output value at the output node follows an output target value at the output node. The control unit is configured to change the output of part of the plurality of power supply circuits when there is a deviation smaller than or equal to a predetermined value between the output value and the output target value.