State Estimation in a Power System by Utilizing EKF and UKF

In this paper, state estimation for a power system including a synchronous generator connected via a tie-line to an infinite bus is considered. The highly nonlinear 7th order model is considered for the synchronous generator. Several simulations are carried out for different cases including transition period, astep change in the input torque and a 3-phase fault at the machine terminal. In each case, process and measurement noises are considered for the system and unscented kalman filter (UKF) is employed for state estimation. Finally, the results obtained by applying UKF are compared with the well known ExtendedKalman Filter (EKF). Simulation results show that in this power system, at the beginning time of simulation UKF has better performance in state estimation than EKF, but after passing this transition period and also in the period that input torque is changed, EKF has better performance and finally with a 3-phasefault, performances of both filters are approximately the same

کلیدواژه ها:

state estimation ، synchronous generator ، power system ، unscented kalman filter