Bi-directional converter with buck/forward active clamp

This paper presents a bi-directional converter with a buck/forward active clamp, which can be used in 360 V dc-link and 100 V battery of a dc generation PV system. This topology can achieve turn-on and turn-off zero-current-transition (ZCT). In buck operation mode, the converter is operated with synchronous rectification and with an active clamp, which is realized with a forward snubber. With this snubber, a coupling inductor is introduced to smooth reverse recovery current and the energy absorbed in the buffer capacitor can be recycled to the sources. For boost operation mode, the coupling inductor is also used to smooth reverse recovery current during turn-on transition, and a buck snubber is introduced to function as the forward one. Additionally, the inductor of the buck snubber is coupled to the secondary winding of the forward transformer, which not only reduces the number of cores but ensures normal operation of the buck and the forward. Simulated results have confirmed the operation mode and the features of turn-on and turn-off ZCT.