Online Monitoring of Wide-Area Voltage Stability Based on Short Circuit Capacity

Short circuit capacity is an effective indicator of voltage stability. In this study, an online monitoring system of wide-area voltage stability based on short circuit capacity is proposed. Firstly, the relation of short circuit capacity and voltage stability is briefly illustrated, and the voltage stability index based on short circuit capacity (VSIscc) containing the impact of both the load side and system side is proposed. Simulation on WSCC 9-bus system demonstrates the effectiveness and correctness of the VSIsccSecondly, a framework of the online monitoring system is carried out. In which the power system is divided into several Voltage Monitoring Areas (VMAs) and the optimal placement of Phaser Measurement Units (PMUs) is obtained. The visualization of the result is added to the system to enhance intuition and impression of the monitoring system. Finally, a practical application of proposed monitoring system in a large interconnected power system is provided, and the analysis of an actual low-frequency oscillation demonstrates the effectiveness of our system to trace the dynamics of voltage level.