Improving grid fault tolerance by optimal control of FACTS devices

One of the most promising applications of the family of electronic devices called Flexible AC Transmission System (FACTS) devices is to better regulate power flow in transmission grids. In particular, the Unified Power Flow Controller (UPFC) is the best choice for complete control of power flow control. By selecting proper installation locations and control techniques, UPFCs may be able to prevent the “domino effect,” where a single fault leads to a widespread blackout. Due to installation costs, it is hoped that only a small number of devices will be needed to effectively regulate a large grid, however, selecting the optimal number of devices, identifying the best possible installation locations, and finding a technique for coordinated control of these device are still active areas of research. In this paper we provide empirical evidence that common optimization techniques may be used to identify control settings for UPFCs. The evidence indicates that the optimization techniques lend themselves to real-time use, but they may also be used during the planning phase to help identify the best possible installation locations for UPFCs.