On-Line Voltage Stability Monitoring and Control (VSMC) System in Fujian power grid

The main functions and implementations of Fujian on-line voltage stability monitoring & control (VSMC) system is presented in this paper. The salient feature of VSMC is that the on-line voltage stability close-loop control is realized partly by interfacing with the existing automatic voltage control (AVC) system. Within the scan period of 5 minutes, the load margins of current operational state and about 260 credible contingencies are computed at totally 10 different predefined load directions. Once the unstable or severe contingencies are identified, the preventive control module is activated to produce the preventive control actions and the new voltage lower limits of all pivot buses are given to AVC system. A sensitivity-based successive linear programming method is used to obtain the control solution robustly. Fujian on-line VSMC system helps operators to monitor the voltage stability margins and automatically take actions to mitigate the voltage collapses.