Harmonics extraction of nonlinear load operating in wide frequency variation

Active filters are used to mitigate the harmonics drawn by the non-linear loads. Performance of active filter is highly influenced by the method used to obtain the current reference. There are many ways of generating this reference current. Most of these methods may not do its best when operating/grid frequency varies. In this paper two methods are developed, Approximation Method and Rigorous Method, for the unit vector construction which works in wider frequency variation. A single phase active filter is realized to validate the unit vector experimentally. Experimental results verifying performance of unit vector construction method and operation of active filter are also given.