逆变器输出直流分量检测与抑制方法

为消除逆变器交流输出的直流偏置电压,提出了一种检测电路与抑制方法。该检测电路由低通滤波、隔离跟随、调理放大等硬件电路组成,可以精准提取直流偏置电压,并具有一定抗共模干扰的能力。所得到的直流分量,经控制系统调整得到直流反馈量,并叠加到基波后,经电压与电流的双闭环系统调节直流分量。通过10 kVA的逆变器实验平台验证了该检测电路与抑制方法,直流偏置电压的抑制效果明显优于常用的检测电路及抑制措施,且能够在较强的电磁干扰下获得理想的抑制效果。实验结果表明所提出的直流分量检测电路与抑制方法可行。

A Method of Detecting and Suppressing Inverter DC Bias

In order to eliminate the DC bias voltage of the inverter AC output,a detection circuit and a suppression method are proposed. The detection circuit is composed of low-pass filter,isolation follower,and amplification circuit. It can accurately extract the DC bias voltage,and also it has a certain ability to resist common mode disturbance. The obtained DC bias voltage is adjusted by the control system,and the calculated DC bias feedback is added to the fundamental wave,and then the DC bias is adjusted by a double closed-loop system of voltage and current. Through the 10 kVA inverter experimental platform,the detection circuit and suppression method are verified,and the experimental effect is significantly better than the commonly used detection circuits and suppression measures,and it can obtain the ideal suppression effect under strong electromagnetic interference. The experimental results show that the proposed DC bias detection circuit and suppression method are feasible.