一种APF直流侧电压波动分析及其吸收电路设计

An APF DC-link Voltage Ripple Analyse and Absorbing Circuit Design

此处根据瞬时功率平衡理论,对并联有源电力滤波器(SAPF)的直流侧电压波动进行了详细地分析,得到了SAPF直流侧产生波动的原因,并建立了相应的模型。更进一步地分析发现直流环节电压纹波会严重影响SAPF的输出电流畸变率,从而影响SAPF的补偿性能。因此,此处设计了一种直流环节电压纹波抑制电路(RSC),此处设计的RSC可以吸收SAPF直流侧上的纹波电压至RSC中,降低SAPF原有的直流侧电压波形,从而使SAPF电压纹波不影响SAPF桥臂的输出电压。并且,由于RSC的电压波动与输出桥臂隔离,不会影响SAPF输出电压,因此,RSC上的允许电压波动可以大大提高,从而可以降低直流环节电容值,并且提高SAPF的补偿性能,提高整体功率密度。实验结果表明了该方法的有效性。

A DC-link voltage ripple model of shunt active power filter(SAPF)is built according to the instantaneous power balance theory,and the cause of DC-link voltage ripple is analyzed and it is found that DC-link ripple will seriously affect the SAPF compensation performance.Based on this,a DC-link voltage ripple suppression circuit(RSC)is designed.The additional RSC can absorb the ripple voltage on the SAPF DC-link,and the absorbed voltage ripple on the RSC does not affect the output voltage of the SAPF bridge arm,so the allowable ripple can be greatly increased.Therefore,the value of the DC-link capacitor can be greatly reduced,which improves the compensation performance of the SAPF and improves the overall power density.The results of the experiment show the validity of this method.