Coordination of PSVR and PSS parameters in multi-machine system

YU Jiatong; WANG Kewen; LIU Wenjun; CHEN Mengru; CHEN Jian; JIANG Songfang

doi:10.16186/j.cnki.1673-9787.2022010046

Abstract：Objective To improve the power angle and voltage oscillation characteristics of the multi-machine power system as a whole,Methods the power system voltage regulator(PSVR)was introduced into the multi-machine power system with PSS,the interaction between voltage oscillation modes and power angle os-cillation modes was considered,and PSVR parameters were set reasonably.In this paper,the initial values of PSS and PSVR parameters were set by phase-frequency characteristic analysis and root locus method re-spectively.Then,gain coefficients and time constants of the controllers were used as control variables,stabil-ity indices of power angle oscillation modes and voltage oscillation modes as optimization objective,and the permitted range of controller parameters as the constraint condition,the joint optimization model of PSS and PSVR parameters were established.Finally,the optimization model was solved by the nonlinear programming method.Results Through the analysis of practical examples,through coordinated optimization of PSS and PSVR parameters,the power angle oscillation modes and voltage oscillation modes of the system improved,and the damping ratio of both reached the expected level.In the 8-machine system,the damping ratio of the minimum damping power angle mode increased from 0.0841 to 0.1029,and the damping ratio of the mini-mum damping voltage mode increased from 0.0475 to 0.0911.In the practical system,the minimum damping mode of power angle and voltage oscillation modes could also reach the threshold value after optimizing.Conclusion Introducing PSVR into the multi-machine system with PSS,the joint optimization model of PSS and PSVR parameters proposed in this paper could improve the power angle and voltage oscillation charac-teristics of the system as a whole.