Voltage Security Assessment of Power System

This paper deals with the security aspects of power system by evaluating the severity of transmission line outage. Voltage security assessment is made by determining the power flow in the line using load flow for each contingency. The severity of contingency is measured using a scalar index called Voltage performance index. 1P-1Q Method and Fast Decoupled load flow are used as approximate and exact load flow methods for Voltage security assessment respectively. Contingency analysis is carried out and ranked lists in the decreasing order of severity based on Voltage Performance Index values are prepared for standard test systems. The severity of line is evaluated and compared using these load flow methods.