An improved phasor assisted state estimator

Conventionally, state estimation programs are being run at an interval of 3-5 minutes in modern energy management systems. The wide area monitoring system (WAMS), utilizing synchro-phasor data, offers a great promise in improving the system state estimation. The phasors can be acquired and refreshed at every 20-50 ms. This paper presents a new method to obtain a more accurate and faster method for power system state estimation. The accuracy has been improved by using phasor measurements along with supervisory control and data acquisition (SCADA) measurements in the traditional weighted least square (WLS) state estimator. Faster convergence has been achieved by using phasor measurements which are available between the two consecutive state estimation runs. The effectiveness of the proposed method has been established on three test systems, viz. the IEEE 14-bus system, New England (NE) 39-bus system and Northern Region Power Grid (NRPG) 246-bus Indian system.