A voltage regulator using multi-parallel-connected series-voltage compensators

A modular and scalable concept of voltage regulation for enhancing service continuity and increasing power rating in single-phase series voltage regulator is proposed. It is based on paralleling multiple series-voltage compensators, namely Multi-Parallel-Connected SeriesVoltage Compensator (MSVC), to perform output voltage regulation. The output current of each compensator is coupled to another one through a coupling transformer. Thus, the load current is shared near-equally among the compensators. The operating principle, the steady-state and transient current-sharing characteristics will be described and discussed. A 3kVA MSVC test bed with three parallel-connected compensator units has been built and evaluated.