A new robust identification method for Xq of synchronous generator with steady-state PMU data

This paper proposes a robust on-line identification method for the synchronous generator´s quadrature-axis synchronous reactance Xq with steady-state PMU (Phasor Measurement Unit) data. Firstly, the mathematical formulation for identification of Xq, which is a least square estimation with the objective of terminal voltage fiting is introduced. And then, the robust Huber estimation, which can eliminate the effects of gross errors among measured data, is presented. Furthermore, the Huber estimation is applied to identification for Xq by modifying its objective function. Simulation results with PSASP data verify the high accuracy and robustness of the proposed method in different situations. Moreover, simulation results with the field data of a 667-MVA generator show the effectiveness of the proposed approaches.