Coordinated Mitigation Actions for Controlling Voltage Violation Occurrences in Operation

This paper proposes an optimization approach to find optimal control actions required to mitigate voltage limit violations in transmission networks. Voltage limit violations occur more often as a consequence of contingencies in the network. In extra-high voltage transmission systems, the possibility of violating high voltage limit increases during light load periods. Now, light loading conditions happen more frequently due to integration of renewable energy resources (RES) in distribution systems. On the other hand, violating low voltage limit is an indication of reactive power deficiency in the system. Control actions considered in the proposed optimization approach include switching capacitor/reactor banks, switching transmission lines, changing tap position of transformer taps, and adjusting voltage setpoint of regulated buses. Upon the occurrence of voltage limit violation, available control variables within the area of interest would be considered in the optimization approach, while control variables in neighboring utilities would be fixed. Results from 2000-bus synthetic grid and EMS cases of different actual systems with high/low voltage limit violations are used to demonstrate the applicability and effectiveness of the proposed optimization approach.