International Journal of Engineering and Technology

in this paper a concept of generalized theory of instantaneous imaginary power is proposed for a three-phase four-wire system. Unlike instantaneous reactive power theory in which a complex mathematical transformation is used for controlling action of shunt active power filters. The proposed control strategy is simple and further to reduced its complexity the line current vector is decomposed into two orthogonal components without mathematical transformations. The developed control strategy has been tested for three-phase four-wire system feeding non-linear load. The obtained results show satisfactory performance for a number of actual system conditions such as load changing of non-linear load. The THD (total harmonic distortion) on supply side with shunt active power filter complies with IEEE harmonic standard, which validates the satisfactory implementation of proposed theory.