The power conversion system

The present invention provides a power conversion system, comprising: a power conversion circuit comprising a first arm and a left arm; secondary electric power conversion circuit that includes a secondary arm and the secondary left arm; and a control circuit, by the primary coil to a secondary coil magnetically coupled to the primary power converter controls power transmission between the secondary circuit and the power conversion circuit. To switch between the left arm and the lower transistor in said primary power conversion circuit in the right arm of the control circuit based on the transistor off time off time of the power conversion circuit primary and secondary power conversion circuit between the terminal voltage waveform of the phase difference and the phase difference of the secondary power conversion switching transistor between the transistor and the lower left arm right arm circuit is set so that the primary coil and the secondary coil the phase difference is 0 and the duty voltage waveform terminal equal to each other.