Real Time Stability Index for Angle Stability Assessment Using Synchrophasor Data

Abstract

The stress on the power transmission network has been increasing in recent time due to deregulated energy market, environmental constraints and limited investment in the transmission system. Hence, the power system is enforced to operate nearer to the stability limit and due to which it is required to estimate the system operating point as fast as possible with higher accuracy to maintain the system stability. The objective of this paper is to formulate Real Time Stability Index (RTSI) to obtain loadability of the power system. RTSI is determined from synchrophasor data which are obtained from phasor measurement unit placed at the bus terminals. The synchrophasor data are used to calculate the angle difference between two Thevenin equivalent sources which ensures loadability of the power system under given operating conditions. RTSI can be used effectively for accurate measurement and monitoring of loadability of the system. The results obtained from RTSI are evaluated for 29-bus Hydro-Quebec system under different operating condition.      

Keywords:  Phasor Measurement Unit, Power System Stability, Real Time Stability Index, Wide Area Monitoring System