Study on an improved harmonics detecting method based on instantaneous reactive power

This paper presents an improved harmonics detecting method based on theory of instantaneous reactive power. This improved method substitutes traditional low-pass filter (LPF) by integrator, delay and gain, which can reduce delay time of the harmonics detecting to 1/6 of source period, and it is implemented in software using DSP chip. The simulation and experimental results indicate that the improved method has characteristic of fast dynamic response, it can meet the precision and the good real time of harmonics detection, also it can be realized easily.