Development of an Index for Preventive Control Ranking and Selection for Voltage Stability Analysis

Preventive control selection for voltage stability concerns with determining the preventive controls that have to be activated, and finding a coordination between these preventive controls. This work develops an index, namely correction index CI, that can be used to rank the preventive controls for voltage stability analysis. This ranking helps the operators to select the most effective preventive controls to simultaneously mitigate the impacts of system contingencies on the critical buses. In other words, if such index is used for control selection, the useless (or less effective) controls can be ignored. This index is based on the degree of the effectiveness of the preventive controls to improve the voltage stability margin of power systems. The index can measure the efficiency of each preventive control not only to one bus (i.e. pilot bus), but to multiple critical buses of the system. The cost aspect is also involved in index calculation to distinguish between the cheap and the expensive controls. This means that the correction index helps the operators to select only the cheap and the high-effective controls. The proposed method is tested on the IEEE 39 bus network under a contingency scenario. The results show that the proposed index is accurate and valid for control ranking.