Research And Achievement Of Harmonics Detection Based On A Fuzzy Step Size Adaptive Algorithm

Harmonic detection algorithm is studied in this paper, and especially on minimum mean-square (LMS) adaptive harmonic detection algorithm. A fuzzy step size LMS algorithm is proposed in this paper. For this algorithm a harmonic detection device based on two DSP systems is designed and made to test and verify the feasibility of this algorithm.First, several harmonic detection algorithms that are common used are studied. LMS adaptive harmonic detection algorithm is finally chosen for harmonic detection in this paper. At the same time the defect of this algorithm is also considered, so a fuzzy step size LMS algorithm which is combined with the fuzzy control theory is used in this paper. MATLAB software is used to simulate, then the harmonic detection result is analyzed.Then, the signal acquisition device of power system and software development board are designed. The signal acquisition device is used to gather the harmonic currents which go through the load and generate sinusoidal synchronous with the power system voltage.Software development board is also designed which is made up of two TMS320F2812 and a dual-port RAM. One DSP is used for data collection and data processing, and another is used for harmonic detection. The communication of the two DSP is the dual-port RAM.At last, with the system designed above, the harmonic detection device is tested, including the gathering of the harmonic currents, the generating of sinusoidal synchronous with the power system voltage and the realizing of the fuzzy step size LMS algorithm.The rusult of the test proved the accuracy and feasibility of this algorithm.