Case Study: Smart Automatic Synchronization in Islanded Power Systems

Automatic synchronizing systems are used to reconnect multiple islanded power grid sections. These systems are required to function automatically with minimal human supervision because they must dispatch multiple generators simultaneously to reduce slip and voltage difference at the interconnection point. This paper describes a smart automatic synchronizing system that can connect multiple generators in an industrial power system during islanded and utility-connected modes via six different bus-tie and utility tie breakers. The automatic synchronizing system performs matching by controlling multiple governor and exciter interfaces within the facility. Controlling slip and voltage difference across any of the six different breakers in any combination is accomplished with up to six different and simultaneous power system islands. The power system studied is a large refinery containing six generators, totaling about 260 MW of generation. The functionality, operation, and validation of this automatic synchronizing system using real-time-digital-simulator tests are discussed.