谐波电流检测新方法及在有源电力滤波器中的应用

A New Harmonic Current Detection Algorithm and Its Application in Active Power Filter

针对现阶段对电网谐波电流检测方法中,普遍存在工频周期时延、计算量大等不足,提出了一种基于单相电压同步坐标变换的检测方法.该方法利用单相电压构造同步旋转角,不管在三相平衡系统还是不平衡系统中都能有效检测出电网谐波电流,并且不需要锁相环电路就可以获得同步旋转角,消除了PLL延时带来的影响.仿真与工程实际表明:该算法能有效提高系统的实时性、目标跟随能力,更适合于有源滤波器的工程应用.

To avoid some shortcomings of harmonic current detection methods, such as cycle delay and large computation, a harmonic current detection algorithm based on single phase voltage synchronous reference frame transformation was presented. This algorithm can detect the harmonic current effectively not only under the bal- anced source, but also under the unbalanced source. Furthermore, this algorithm forms the single phase voltage to synchronous rotary angle, thus eliminateing the influence brought by the time delay of PLL when using tradi- tional dq transformation algorithm. Simulation and experiment results have shown that the proposed algorithm can enhance not only APF＇s real-time response, but also its current-tracking effect, so that it is more suitable for the APF＇s application in engineering.