一种基于瞬时无功功率的改进p-q谐波电流检测方法研究

针对传统的谐波检测算法在检测三相电压对称时效果良好而不对称时存在很大误差的问题,提出一种新型的既适用于三相电压对称系统又适合三相电压不对称系统的高精度改进p-q谐波检测方法.该谐波检测方法应用正负序解耦理论提取三相电压的基波正序电压分量,通过给定的谐波拟合精度与相对误差等指标进行相应的跟踪计算,从而实现谐波电流的准确检测.通过仿真和实验表明,提出的谐波检测方法与传统方法相比具有较大的优势,精度、有效性和抗干扰性能表现良好.

Research on an improved p-q harmonic current detection method based on instantaneous reactive power theory

How to detect the harmonic current quickly and accurately is a key factor of the active power filter whole performance. The traditional harmonic detection algorithm based on instantaneous reactive power theory has a good effect under three-phase symmetrical voltage, but when the three-phase voltage is unbalanced, the measurement results will have big error. In order to solve this problem, this paper proposed an improved harmonic detection method based on instantaneous reactive power theory, which is not only suitable for three-phase symmetrical voltage system but also for three-phase asymmetrical voltage system. The proposed method extracted fundamental positive sequence voltage from three-phase voltage using positive and negative sequence decoupling method, calculated the tracking performance with corresponding accuracy of fitting and relative error, and then realized the high-accuracy measurement of harmonic current. Through simulations and experiments, the proposed harmonic current detection method based on instantaneous reactive power theory is proven to be effective and reliable, and its measurement accuracy, effectiveness and anti-interference performance are better than the corresponding features of traditional harmonic detection method.