PMU placement for voltage stability assessment and monitoring of power systems

The use of PMUs is proving an important basis for online voltage stability assessment and monitoring. Due to the relatively high costs, it is essential to investigate the possibility and method to reduce the number of PMUs. This paper first introduces an analytical equivalent circuit and approach for online voltage stability assessment. Second, an analytical index is proposed to calculate the factors to influence the system voltage stability. Finally, a PMU placement method is proposed to reduce the number of PMUs and to determine their locations for online voltage stability assessment and monitoring. Case studies have been conducted on the IEEE 30 bus system, and the results show that only few buses with heavy loads have big impacts on the system voltage stability, which verifies the effectiveness of the proposed PMU placement method.