两级DC/AC变换器直流输入电流纹波抑制

Direct Input Current Ripple Reduction in Two-stage DC/AC Inverter

两级单相逆变器的前级DC/DC变换器输入电流会含有较大的低频纹波电流,这会严重影响直流侧电源的寿命。此处基于电流反馈双半桥(CF-DHB)DC/DC变换器和全桥逆变器构成的两级DC/AC变换器,提出一种新的抑制输入电流纹波的方法,根据变换器的瞬时功率特性,计算出消除电流纹波所需的移相角,进而消除控制器输出量中的纹波分量。能够在保证交流输出电压质量的同时,显著抑制输入电流纹波,并且能够消除负载突变时的电流振荡。实验验证了所提控制方法的有效性。

As for the two-stage single-phase inverters,the input current of the front-end DC/DC converter will contain large low-frequency ripple current,which will seriously shorten the life span of the DC sources.Based on the two-stage DC/AC converter which consists of a current-fed dual-half-bridge (CF-DHB)DC/DC converter and a full-bridge inverter,a novel method to suppress low-frequency current ripple is proposed.The proposed method gets the needed phase shift angle for reducing current ripple according to the instantaneous power characteristics of the converter,and can eliminate the ripple components in the output of the controller.Through the proposed approach,the low-frequency current ripple can be significantly reduced and the input current oscillations can be eliminated with high quality of AC output voltage.Experimental results validate the performance of the proposed method.