The beneficial effect of filtering in current controlled inverter

Abstract

An approach of harmonics component analysis, portraying the presence of certain amount of harmonics at the inverter output terminal, has been indicated in this paper. Some unwanted impacts are caused by the harmonics such as unbalance and excessive neutral currents, interference in nearby communication networks and disturbance to other consumer, torque pulsations in electric motor drives are and so on. Thus, the minimization of the harmonics contained in the output of a single phase current controlled inverter undergoing hysteresis modulation technique is important so as to get rid of these detrimental effects. With a view to reducing the assumed 3 rd order harmonics, an LC low pass filter is used in this paper that blocks the harmonics and undeniably passes almost a sinusoidal output at the output terminal. It has been found from the simulation that the Total Harmonic Distortion (THD) is just above 33% during the existence of up to 3 rd order harmonics, although it is predicted to be 0% in ideal case, and more importantly, that can be slumped to 0.00003% by the application of an LC low pass filter.