Selective Current Harmonic Elimination in an AC Voltage Controller Drive System using LMS

Selective current harmonic elimination (SHE) is a widely researched and alternative to traditional pulse width modulation (PWM) techniques. This paper presents an adaptive filtering algorithm for the selective current harmonic elimination in ac voltage controller. The algorithm used for adaptive selective harmonic elimination (ASHE) is, "Least Mean Square" (LMS). This method eliminates the dominant harmonics in line current and it requires only the knowledge of the frequency of the particular harmonic to be eliminated. The algorithm was simulated using MATLAB/SIMULINK tool and its performance was analyzed based on total harmonic distortion (THD), magnitude of eliminated harmonics, output voltage and current waveform. The simulation results are validated by the elimination of the fifth, seventh and eleventh harmonics.