High-Gain Zero-Voltage Switching Bidirectional Converter With a Reduced Number of Switches

A nonisolated bidirectional dc-dc converter has been proposed in this brief for charging and discharging the battery bank through a single circuit in applications of uninterruptible power supplies and hybrid electric vehicles. The proposed bidirectional converter operates under a zero-voltage switching condition and provides large voltage diversity in both modes of operation. This enables the circuit to step up the low-battery bank voltage to high dc-link voltage, and vice versa. The bidirectional operation of the converter is achieved by employing only three active switches, a coupled inductor, and an additional voltage clamped circuit. A complete description of the operation principle of the circuit is explained, and the design procedure of the converter has been discussed. The experimental results of a 300-W prototype of the proposed converter confirmed the validity of the circuit. The maximum efficiency of 96% is obtained at half load for boost operation mode and 92% for buck mode of operation.