Using a static VAr compensator to balance a distribution system

An algorithm for applying a fixed capacitor-thyristor controlled reactor (FC-TCR) type of static VAr compensator (SVC) in the distribution system to dynamically balance a system is introduced. With a newly developed individual phase control scheme, an SVC can reduce negative sequence current caused by the load to improve system balance. Since the control circuit is governed by a microcomputer, which replaces the traditional discrete load switching and makes the capability of rapid and dynamic balancing of the system become possible. In addition, the power factor can be improved simultaneously by selecting an appropriate amount of capacitive/inductive compensation. This paper presents a mathematical model for computer simulation and control of a delta connected SVC to achieve the purpose of negative sequence reduction. Some computer simulation and scaled laboratory test results are discussed.