Estimation of harmonic voltages using Independent Component Analysis

Non-linear loads like the electric arc furnace and PWM inverters generate voltage harmonics on a large scale. Arc Furnaces generate even order harmonics and certain odd order harmonics not commonly present in other loads. Under such a situation application of conventional Independent Component Analysis (ICA) methods is not possible. So, certain modifications have to be incorporated to the existing ICA methods. Modified FastICA and JADE are the two ICA algorithms considered in this paper. Efficient Variant ICA (EFICA) has better accuracy than FICA in the presence of finite samples, but it is not attempted in this paper as performance is given more importance than accuracy. A simple five bus system with the electric arc furnace and the PWM inverter is investigated by applying the modified JADE and Fast ICA algorithms. The simulation results of the work point a compromise between accuracy and performance. This arises as the FastICA (or EFICA) collapse when only one independent component exists.