电力系统谐波的一种新的单相检测法

在瞬时无功功率理论的基础上,针对一般基于d-q变换的检测方法不能检测不对称三相电流的谐波的缺点,提出了一种新的电网谐波检测方法。此方法属于单相检测法,先提取电网电流中的某相基波幅值,再将基波幅值乘以与该相电流同相位的正弦波,从而得出该相的瞬时基波电流。该方法相对简化了结构,并且采用了改进的算法,能很好地运用于单相电路和三相电路的谐波检测。仿真结果表明,在电网三相电流对称和不对称的两种情况下,这种方法都能保证检测的实时性和精确性。

A new method of single-phase measurement for power system harmonics

Based on the instantaneous reactive power theory, this paper presents a new harmonic detecting method in contrast to the methods which involve d-q transform and can not work under unbalanced currents. This is a single-phase measurement that multiplies the amplitude of fundamental current of a line by a sine signal which has the same phase with the current. With simpler block structure and improved algorithm, the proposed method performs well both in single-phase circuits and three-phase circuits. The simulation shows that this method is of real-time and accuracy under both balanced and unbalanced three-phase currents. This project is supported by National Natural Science Foundation of China(No.50337010).