基于输入导纳模型的AC-DC变换器输出电流二倍工频纹波的抑制

Suppression of Double-Line-Frequency Output Current Ripple of an AC-DC Converter Based on an Input Admittance Model

采用高功率因数(Power Factor,PF)的AC-DC变换器通常在二倍工频处具有显著的输出电流纹波。为了抑制这种低频输出电流纹波并保持高功率因数,可将并联补偿电路(Parallel Compensation Circuit,PCC)的输入侧与功率因数校正(Power Factor Correction,PFC)变换器的输出侧并联。建立PCC的输入导纳模型,提出一种基于虚拟导纳的输入电压前馈(Voltage Feedforward,VFF)策略,实现对PCC输入导纳的整形,从而有效抑制AC-DC变换器的输出电流二倍工频纹波,最后通过仿真验证了分析结果。

An AC-DC converter with high power factor (PF) usually suffers from a significant output current ripple at double line frequency. In order to suppress such low-frequency output current ripple and maintain high PF, a parallel compensation circuit (PCC) is connected in parallel with the output of a power factor correction (PFC) converter. In this paper, an input admittance model of the PCC is established. To further reduce the low-frequency output current ripple, an input voltage feedforward (VFF) control with a virtual impedance is presented which realized the shaping of the input admittance of PCC, so that the output current ripple of AC-DC converter can be effectively suppressed. Finally, simulation results showed the analysis is correct.