Bi-directional converter

PROBLEM TO BE SOLVED: To provide a bidirectional converter capable of suppressing the occurrence of reverse currents in a start-up time in the case of continuously controlling step-up/step-down or charging/discharging.SOLUTION: The bidirectional converter includes: a switch element Q1 connected to the positive electrode side of an input/output terminal T1 and one end of a coil L; a switch element Q2 connected to the negative electrode side of the input/output terminal T1 and one end of the coil L; a switch element Q3 connected to the positive electrode side of the input/output terminal T2 and the other end of the coil L; and a switch element Q4 connected to the negative electrode side of the input/output terminal T2 and the other end of the coil L. In a normal time, the switch elements Q1 and Q2 are configured to complementarily operate, and the switch elements Q3 and Q4 are configured to complementarily operate, and to bidirectionally convert a voltage and power. In a fixed period from a start-up time to the normal time, at least one of the switch elements Q1 to Q4 which are turned on in the normal time is turned off, and at least one combination between the combination of the switch elements Q1 and Q2 and the combination of the switch elements Q3 and Q4 is not configured to complementarily operate.