Eigen-Analysis Considering Time-Delay and Data-Loss of WAMS and ITS Application to WADC Design Based on Damping Torque Analysis

Abstract

Data-loss from wide-area measurement systems (WAMS) is a stochastic event and eigenvalues of power systems containing data-loss cannot be calculated directly. This paper proposes a unified model of WAMS data containing time-delay and data-loss according to its mathematical expectation. Based on Pade approximation, the model is incorporated into a system linearized model with WAMS. Thus, an eigen-analysis can be conducted to analyze the impacts of data corruption and to calculate the system stability time-delay margin. Then, the unified model is applied to damping torque analysis (DTA) to derive the damping torque index (DTI) with WAMS. The DTI can be used to select feedback signals and conduct the parameter design of a wide-area damping controller (WADC). Finally, the 2-area 4-machine (2A4M) Kundur system and Eastern China power grid (ECPG) are simulated to validate the feasibility of the model and its application. The results demonstrate the impacts of data corruption on system dynamic performance and the ability of the method to improve the small-signal stability of interconnected power grids.