Study On The Influence Of IEEEAC5A Excitation System On Stability Of Power System Based On The Particle Swarm Optimization

The excitation system provides exciting current for the generator excitation and is very important for voltage stability, whose characteristics have a great impact on the stability of the system. Increasing the excitation system amplification can achieve fast excitation and improve the system operation at the same time. But the increase of the amplification factor may reduce the damping of the system or become negative. When the system is subjected to external disturbance, it may cause low frequency oscillation due to insufficient damping.In this paper, the parameter tuning of PID excitation controller based on particle swarm optimization algorithm is studied and integral of time absolute value of error performance index (ITAE) is used as the objective function. Through the discretization of transfer function and combined with the difference method, the specific expression of the objective function is derived and write the optimization program and graphical user interface. Finally, this paper uses step signal simulating the no-load start up process to simulate and compare with the results of the experience method. The results show that the PID parameters determined by the method of this paper is better than the control effect of PID parameters selected by the empirical method.In this paper, the effect of excitation control system on low frequency oscillation in three machines nine nodes system is studied by using eigenvalue analysis method. With the linearization of nine machine three node system, the calculation process of the state matrix is derived. By calculating the characteristic value, damping ratio and the electrical and mechanical circuit correlation ratio and other information that is strongly associated with oscillation characteristics, the influence of the excitation system of PID control on the low frequency oscillation of multi machine system is analyzed.In the simulation analysis of the system, this paper uses the electromagnetic transient program ETSDAC to customize the system. The simulation results show that the PID controller based on particle swarm optimization algorithm has a good regulation effect on the generator excitation voltage and in the system voltage stability also has a very good effect, but the low frequency oscillation of the system is exacerbated. Analysis of the reasons, mainly due to when tuning the parameters of PID controller this paper uses the integral of time absolute value of error minimum principle, whose main purpose is to control the voltage stability and not to take into account the suppression of low frequency oscillation. The suppression of low frequency oscillation can be solved by the power system stabilizer (PSS).