半无桥Boost PFC变换器平均电流控制的设计

Design of Average Current Control for the Semi Bridgeless PFC Converter

半无桥Boost功率因数校正(PFC)变换器拓扑在新能源领域有着重要研究价值,为合理设计变换器控制电路,以实现变换器宽范围的动态特性,此处建立了半无桥Boost PFC变换器小信号模型,并据此推导出基于平均电流控制的双闭环控制系统中电压控制环和电流控制环的传递函数,提出了补偿网络的参数设计方案,确保了变换器的动态特性和稳态特性。在此基础上,设计了一台开关频率100 kHz、额定输出400 V/600 W的原理样机,验证了基于平均电流控制电路参数设计方案的可行性和理论分析的正确性。

The semi-bridgeless Boost power factor correction(PFC)converter has important research value in the field of new energy.In order to reasonably design the control circuit to realize the wide-range dynamic characteristics of the converter,a small signal model of the semi-bridgeless Boost PFC converter is established.According to this,the transfer functions of the voltage control loop and the current control loop in the double closed-loop control system based on average current control are deduced,and the parameter design scheme of the compensation network is proposed to ensure the dynamic and steady-state characteristics of the converter.On this basis,a principle prototype operating at 100 kHz switching frequency,400 V/600 W rated output is built to verify the feasibility of the parameter design scheme and the correctness of theoretical analysis based on the average current control circuit.