Hexagram converter for static VAR compensation

A new multilevel converter - Hexagram converter is proposed for static VAR compensation in high-voltage high- power applications. The new converter is composed of six three- phase two-level standard voltage source converter (VSC) modules interconnected through inductors. It has the advantages of modular structure leading to easy construction and maintenance, no voltage unbalance, low voltage stress, low dc energy storage, and easy control with well-developed VSC control techniques. In the paper, One-cycle control (OCC) - an excellent control scheme for power converter is employed and extended to control the hexagram converter for VAR compensation. Simulation and experimental prototypes have been implemented and well verified the proposed converter along with the proposed control method.