Design of a harmonic-free hybrid STATCOM for load balancing purposes

In this paper, a hybrid harmonic-free Static Synchronous Compensator (STATCOM) is designed for load current balancing and other power quality purposes in 110V, 60Hz low power distribution systems. It integrates the fast response of the switched capacitors-based static Var compensator (SVC) and the linear response of an inductive half-bridge STATCOM. Two switched capacitors work in tandem with the inductive STATCOM to linearize the SVC stepping response. In contrast, the inductive STATCOM is a half-bridge voltage source converter (VSC) with a linear modulation index control for generating pure and harmonic-free inductive current. The devised STATCOM is designed using PSpice and tested on its simulator. The simulation results guaranteed that the designed hybrid STATCOM has harmonic-free operation and fast response in both modes of operation (capacitive and inductive), dynamic load adaptation (for loads like arc furnaces), linear, and continuous control. Based on the advantages of both active and reactive power compensation in flexible AC transmission systems (FACTS), this design offers a reliable, affordable solution for power factor correction and harmonic-free load balancing.