A compact algorithm for three-phase three-wire system reactive power compensation and load balancing

A compact control algorithm for reactive power compensation and load balancing with the static VAr compensator (SVC) in three-phase three-wire power systems is developed in this paper. Each phase susceptance of the SVC can be obtained from a very simple function of voltage and power signals which are measured by a three-phase voltage transducer and two single-phase active and reactive power (P-Q) transducers at the load bus. The calculation of compensation susceptances is based on the criterion of a unity power factor and zero sequence currents after compensation. A simulation is made, as the first stage, to show the validity of the proposed compensation algorithm. Then, a laboratory size microcomputer-based SVC, which consists of thyristor-controlled reactors (TCRs) and fixed capacitors (FCs), is designed and implemented. Simulation and experiment results show that the algorithm is very suitable for online control of the SVC which is designed for phase balancing and power factor correction.