Online Tracking of Thévenin Equivalent Parameters of Power System Based on PMU Data and Discrete Fourier Transform

The significant benefits associated with Thevenin Equivalent (TE) of power system attracted many researchers to develop techniques for estimating TE parameters of power systems. In this paper, a new algorithm is presented for TE parameter estimation. The proposed technique estimates TE parameters of power system by applying Discrete Fourier Transform (DFT) on measurements obtained from Phasor Measurement Unit (PMU). The proposed method utilizes five consecutive PMU measurements for parameter evaluation. The validation of the proposed method is proved for accurate voltage and current measurements. Then, measurement errors are considered and the calculation procedure for the inclusion of such errors is stated. A simple 2-bus test case is considered for validation of the proposed method. The proposed algorithm is then utilized to estimate the TE parameters for the IEEE 30-bus system. Results of both cases are presented to demonstrate the accuracy of the proposed algorithm for online determination of TE parameters of power systems.