Multi-parallel-connected static synchronous series compensators

A modular and scalable concept of series compensation for enhancing controllability and increasing power flow transfer in future distributed power systems is proposed. It is based on paralleling multiple static synchronous series compensators (SSSC), namely multi-parallel-connected SSSC (MSSSC), to achieve reactive power compensation. Each compensator unit is under autonomous control with its output voltage been regulated and its output current been coupled with another compensator unit through cyclically-coupling transformers. The transmission current is shared equally among the compensators. The modeling, design and analysis of a compensator unit and the entire MSSC in an elementary two-machine system will be presented. The theoretical predictions are verified experimentally on a test bed with three compensators connected in parallel.