Study On The Influence Of Excitation System Reactive Compensation Unit On Low Frequency Oscillation Of Power System

The frequent occurrence of low-frequency oscillation has seriously affected the safe and stable operation of the power system.In order to suppress the low-frequency oscillation,the control measures are often added to the excitation system.Because of the different characteristics of the differential adjustment wiring and the negative adjustment wiring,the influence of low-frequency oscillation is different.Therefore,based on the analysis of single-closed-loop voltage control,the compensation current will be introduced from the excitation adjustment unit,and the influence of the low-frequency oscillation on the power system will be introduced Problem in-depth study.Firstly,the mechanism and analysis method of low frequency oscillation of power system are discussed,and the advantages and disadvantages of each method are compared.Based on the Davean static equivalence method,this paper presents the analysis method used in the study of the influence of the adjustment unit on the low frequency oscillation of the power system.And the simulation model of low frequency oscillation of power system is established in Matlab / Simulink simulation environment.The equivalent circuit of low frequency oscillation is established by using the Thevenin equivalent theorem.The variation characteristics of the measured voltage after the compensation current is introduced are analyzed in detail.It is pointed out that when the generator and the system produce oscillation,the introduction of the compensation current will have a different effect on the performance of the generator excitation control system.Then,in the simulation environment of Matlab/Simulink,the simulation model of generator grid running with different adjustment characteristics is established.According to the simulation results,the introduction of the compensation current will increase the oscillation degree when the generator adopts the negative adjustment wiring method.When the generator adopts the positive adjustment wiring mode,the introduction of the compensation current will weaken its oscillation degree.