A cascaded multilevel converter-based SSSC/BESS

A static synchronous series compensator (SSSC), which is a type of FACTS (Flexible AC Transmission System) device, can inject a near sinusoidal voltage with a variable magnitude into a power system transmission line through a coupling transformer. By incorporating an Energy Storage System into the SSSC, the injected voltage can also have variable phase, which makes the SSSC more effective in improving system performance. Recently, for high power applications, multi-level converters have been introduced into FACTS devices. In this thesis, a cascaded multilevel converter-based SSSC/BESS is applied in a two bus transmission system to provide both active and reactive power compensation. The design of the cascaded converter-based SSSC/BESS, the dynamic performance and a PQ decoupled PI control are presented in the thesis. Additionally, the power control ability and the damping effect of the SSSC/BESS in a two bus system are presented and analyzed --Abstract, page iii