Parameter Estimation of Transient Voltage Signals with an Unscented Kalman Filter

Online parameter estimation of ringdown signals is crucial for analyzing the stability of the power system. This paper aims to estimate the frequency and damping ratio of a transient voltage signal using an unscented Kalman filter (UKF). Traditionally, transient signals in the power system are modeled as the sum of exponentially damped sinusoidal signals, and previous work has been performed to estimate parameters by linearizing the model. However, the proposed algorithm in this paper can approximate parameters without assuming linearity. The performance of this method is evaluated on the IEEE 39-bus system simulated on the PSCAD software connected to the UKF algorithm written in the Python programming language. Simulation results indicate the proposed method detects any fluctuation in parameters accurately.