基于辅助绕组的单级桥式PFC变换器纹波抑制策略

Output Voltage Ripple Suppression Scheme of Single-Stage Full-Bridge PFC Converter Basic on Auxiliary Winding

单级桥式PFC变换器使用一级电路实现功率因数校正及DC-DC变换,导致输出电压存在较大的二倍工频的纹波,影响系统输出特性。传统方式通过增大输出滤波电容的电容量可以降低输出电压纹波,但会导致系统的动态响应变慢。为减小输出电压纹波,本文在基于辅助绕组的单级桥式PFC电路的基础上提出一种纹波抑制策略。抑制策略通过控制辅助绕组的输出电流,降低系统的输出电压纹波,同时能够不影响系统动态响应速度。在提出控制策略的基础上设计了辅助绕组的输出电流、控制电路以及辅助绕组的相关参数。最后进行了实验研究,表明了该策略能够在不影响系统的动态响应特性的基础上降低输出电压纹波。

Because of the special circuit structure of the single-stage full-bridge power factor corrector, there is large output voltage ripple which is double industrial frequency. The output characteristic of the corrector has been influenced. As a conventional method, increasing the output capacitor could reduce the ripple, while the dynamic response is reduced. A novel output-voltage-ripple suppression scheme is proposed in the auxiliary winding single stage full-bridge PFC converter in this paper, which made output voltage ripple lower. Compared with the conventional method, the proposed scheme can solve the problem without influence the dynamic response. The input current of clamp capacitor and the output current of the auxiliary winding have been designed; the control circuit and the constrained conditions of the key parameters have been designed. As the theoretic and experimental proved, output voltage ripple is suppressed by this scheme and the key parameters is validity.