Unified One-Cycle Control for Fully Digitalized ZVS Four-Switch Buck–Boost Converter During Bidirectional Power Flow Transition
Xiangshuai Jia, Deshang Sha, Yining Zhao
Abstract
A unified one cycle control is presented to achieve bidirectional power flow operation for four switch buck boost converter employing fully digitalized control. There are no need for analog comparators or digital to analog converters. Based on new definition of operating modes, the modulation can be unified in both directional operations. One-cycle bidirectional power transition with fully zero voltage switching can be achieved under various voltage conversion gains. And a modified control curve of inductor current is proposed to eliminate the power oscillation during operation and ZVS can be ensured during the transition. A 450W prototype using the proposed full digital control under bidirectional power flow operation is verified successfully.