Contingency ranking for timely power system security assessment using a new voltage-angle index and based on the PMU data

Given the importance of the power system security and the role of the operator in enhancing this feature, improving the operator’s actions and information in the power system management is critical. The proper tools and available information for the operator can continuously improve the power system security. During power system operation, the operator needs to identify probable hazardous contingencies to assess power network security online. Thus, contingency ranking based on their importance has always been of interest to researchers. In present study, a new method is proposed for appropriate contingency ranking and online power network security assessment based on the Phasor Measurement unit (PMU) data. In the proposed method, unlike the previous methods, two voltage and angle indices were used. Since the variables of load-flow studies are used to calculate the proposed index, this index can provide a comprehensive assessment of the network security. The proposed index is implemented on three IEEE 14-, 30- and 57-bus test systems to evaluate its performance. First, using this index, contingency analysis is carried out in 2000 operational points and the obtained results are compared with a randomly selected operating point. The results indicated the performance and response time of the proposed index.