Patent ID: 9209701
Filing Date: 2015-12-08
Classification: H02M

Abstract:
1. An electric power conversion system comprising: a primary electric power conversion circuit including: a left arm including a left arm upper transistor and a left arm lower transistor connected in series with each other at a left arm connection point between a positive electrode bus and a negative electrode bus; a right arm including a right arm upper transistor and a right arm lower transistor connected in series with each other at a right arm connection point between the positive electrode bus and the negative electrode bus; and a primary coil connected and arranged between the left arm connection point and the right arm connection point; a secondary electric power conversion circuit configured similarly to the primary electric power conversion circuit and including a secondary coil corresponding to the primary coil; and a control circuit configured to control transfer of electric power between the primary electric power conversion circuit and the secondary electric power conversion circuit by magnetically coupling the primary coil to the secondary coil, wherein the control circuit is configured to set an interphase difference in switching between the left arm lower transistor and the right arm lower transistor in the primary electric power conversion circuit and an interphase difference in switching between the left arm lower transistor and the right arm lower transistor in the secondary electric power conversion circuit, on the basis of an off time of the primary electric power conversion circuit and an off time of the secondary electric power conversion circuit, such that a phase difference between a terminal voltage waveform of the primary coil and a terminal voltage waveform of the secondary coil is 0 and duty ratios of the terminal voltage waveforms are equal to each other, when the off time of each left arm lower transistor is equal to the off time of a corresponding one of the right arm lower transistors and the off time of the primary electric power conversion circuit is different from the off time of the secondary electric power conversion circuit.