Wide-Area Measurement-Based Nonlinear Robust Control of Power System Considering Signals' Delay and Incompleteness

Abstract

With the wide application of synchronized phase measurement unit (PMU) in power system, the wide-area measurement system (WAMS) has enabled the use of a combination of measured information from remote location for global control purpose. However, the impact of time delays introduced by remote information's transmission in WAMS has to be considered, and the closed-loop power systems need be modeled as time-delay nonlinear systems. Moreover, the wide-area information is incomplete when not all generators in power system are equipped with the PMU. In order to eliminate the effects of power system model's nonlinearity and wide-area information's uncertainty including time delays and incompleteness, a novel approach based on inverse system algorithm and linear matrix inequality (LMI) technique is proposed to design a nonlinear robust integrated controller. Digital simulation demonstrates that the four-machine system under the nonlinear robust integrated control has less settling time, swing times, oscillatory peak value and more critical clear time and better voltage stability performance for various time delays of remote incomplete measured information than that under PID control or nonlinear decentralized integrated control.