An improved method for harmonics detection in single-phase circuits

In view of the features of harmonics in single-phase circuits, the study makes an analysis on harmonics ip-iq detection for single-phase circuits in the way of mathematics based on the instantaneous reactive power theory. Considering accuracy and real-time of the harmonics detection, a much more suitable method for harmonics in single-phase circuits is proposed. In order to perfect the performance of the whole detection system, a feedback process is added to the system. With the application of the elliptic low-pass filter featuring high decay rate in transition zone and a good frequency characteristic instead of traditional Butterworth low pass filter, the method can reduce the influence of time delay of low-pass filter on the detection accuracy. The modelling and stimulation of MATLAB/Simulink proves the method improves the accuracy and speed of dynamic response.