关键词: 图腾无桥PFC变换器, 车网互动, 分数阶微积分, 小信号建模, 分数阶滑模控制策略

Abstract: Aiming at the shortcomings of insufficient accuracy of integer order mathematical model of totem pole bridgeless PFC converter ( TP-BPFC ) and poor dynamic performance of its control strategy. Based on the establishment of TP-BPFC fractional order mathematical model, a fractional order sliding mode control strategy ( FOSMC ) is proposed. The fractional order topology and working mode of TP-BPFC are analyzed by introducing fractional order inductance and fractional order capacitance. The fractional order state space average model of TP-BPFC is constructed. The fractional order small signal model ( SSM ) of TP-BPFC is obtained by separating the AC disturbance of the fractional order state space average model. The expressions of inductor current and duty cycle and output voltage and duty cycle of TP-BPFC working in continuous current mode are derived. The fractional order sliding mode controller of the converter is designed to improve the dynamic performance of the system. Finally, a simulation model and a 3kW prototype are built for verification. The results show that the proposed control strategy has a response time of 0.41 s less than the traditional PI control strategy, a voltage overshoot of 52 V less, and an inductor current THD of 1.36 % lower than the traditional PI control strategy. Therefore, the proposed control strategy has good dynamic characteristics and robustness.

Key words: Totem Bridgeless PFC Converter, V2G, Fractional calculus, Small signal modeling, Fractional order sliding mode control strategy