Optimization Approach to Parametric Tuning of Power System Stabilizer Based on Trajectory Sensitivity Analysis

Abstract—This paper proposed an transient-based optimal parametric tuning method for power system stabilizer (PSS) based on trajectory sensitivity (TS) analysis of hybrid system, such as hybrid power system (HPS). The main objective is to explore a systematic optimization approach of PSS under large disturbance of HPS, where its nonlinear features cannot be ignored, which, however, the traditional eigenvalue-based small signal optimizations do neglect the higher order terms of Taylor series of the system state equations. In contrast to previous work, the proposed TS optimal method focuses on the gradient information of objective function with respect to decision variables by means of the trajectory sensitivity of HPS to the PSS parameters, and optimizes the PSS parameters in terms of the conjugate gradient method. Since the objective function considers the transient features under large disturbances of HPS, the proposed method could be used to inhibit the spontaneous oscillation caused by small disturbance and to effectively damp the system oscillation caused by large disturbance. Firstly, the application background and traditional parametric tuning optimization methods of PSS are introduced. Then, the systematic mathematical models and transient trajectory simulation are presented by introducing switching/reset events in terms of triggering hypersurfaces so as to formulate the optimization problem using TS analysis. Finally, a case study of IEEE three-machine-nine-bus standard test system is discussed in detail to exemplify the practicality and effectiveness of the proposed optimal method.