基于同步旋转平均值理论的三相谐波电流检测法

摘要

A new current detecting method based on synchronous reference frame and average theory is proposed in view of getting the positive fundamental active and reactive currents in case of nonideal source voltage, delay caused by low pass filter and the accuracy of harmonic current detecting. The delay is shortened with average theory instead of low pass filter. The phase problem of phase locked loop (PLL) is resolved with synchronous rotating coordinate transformation of the three phase voltage and current. The accurate harmonic current is obtained with the difference among the load current, positive fundamental current and negative fundamental current. The feasibility and effectiveness of the detection method is verified theoretic analysis and simulation results.%针对非理想电压下不能获取基波正序有功和无功电流的问题,以及低通滤波器所引起的延时问题,此外还有谐波电流检测的精确性问题,本文提出了同步旋转平均值理论的电流检测法.它通过平均值理论代替低通滤波器缩短了系统延时,对三相电压和电流同时进行同步旋转坐标变换解决了锁相环的相位问题,利用负载电流与基波正序电流和负序电流的差值获得了精确的谐波电流.理论分析和仿真结果证明了该文所提检测方法的正确性和有效性.