State estimation in power system using weighted least squares method

Abstract

State estimation is a key of Energy Management System (EMS) function, used for estimating the state of the power system. Power system may be a quasi-static system and thus changes slowly with time. Since state estimation is computationally valuable, it's difficult to execute it repetitively at short intervals to understand the real time monitoring of such a dynamic system. The state of an electrical power system is characterized by the voltage magnitudes and angles in the system buses. In this state estimation, the states are estimated by weighted least square technique and further the errors due to because of imperfect measurements should be reduced. Static state estimation is performed on the data accessible through the SCADA system. In this estimation the data is acquired through Newton Raphson Load flow analysis. Weighted least square technique evaluates the state of the power system supported the load given to every measurement and it is done for IEEE 14 bus, 30 bus and the results are taken.