VAR management in power systems: Basic objectives, solutions and multi-level converters for STATCOM applications

This paper describes various problems in transmission and distribution systems and demonstrates the significance of reactive power management. Static VAR compensator and STATCOM principles of operation and power characteristics are described. The most common types of multilevel voltage source converters used in STATCOM applications are comparatively analyzed. The most promising topology of multi-level Hexagram converter is adduced. The efficiency of dual-core OCC controller for the non-active current management operational mode of Hexagram converter based STATCOM is proved.