A critical overview on zero sequence component compensation in distorted and unbalanced three-phase four-wire systems

The generalized theory of instantaneous powers has been used in power system applications for compensation of instantaneous powers and harmonic cancellation. Nevertheless, this theory results practically desirable solution in three-phase three-wire systems. However, for a three-phase four-wire system, when the power system is unbalanced or distorted, then these definitions introduce unsatisfactory cancellation of the source zero sequence current. This paper analyzes and simulates this problem to show the issues related to the generalized theory of instantaneous powers. Further, complementary analytical discussions are suggested to remedy the raised problem. Finally, the improved definitions are simulated for a three-phase four-wire system that includes significant zero sequence current. Suggested complementary solutions are then compared with those of conventional generalized definitions, which confirm effectiveness of the proposed solutions in cancellation of zero sequence current of the source.