Optimal Control Method Of Generator Excitation System

The stable operation of power grid is the base to ensure the efficient development of national economy.With the scale and complexity of modern power system increasing,the problem of low-frequency oscill ation become one of increasingly prominent factor to affect the starbility of the system.At the same times,domestic and foreign power systems are affected by low-frequency oscillation,resulting in a number of grid failure events and huge economic losses.Therefore,it is of great signifcant to study the control method for low-frequency oscsillation control and optimize the control parameters.In the traditional sense,the most effective way to control low freuency oscllation is te power system stabilize(PSS)Because the power system is a typ icaal non-linear system,this method is designed on the basis of a smallrange of liearizing model near the operating point of the system,when the operating point of the syste changes,the control performance will inevitably deteriorate.Baased on the theory of non-linear control,this paper also studies the role of non-linear excitation con trooller in improving power system stability.The main work of this paper is as follows:(1)This paper summarzes the basic concepts of power system stability,reviews the development history of power system stabillity ontrol,and briefly summarizes the current research status,including the traditional linear PSS and nonlinear excitaation controller.At the same time,the problems of engineering application and non-linear control method of excitation system are analyzed in this paper(2)The causes of low frequency oscilltion are analyze,and a Heffron-Philipp model is established i MATLAB.The hysteresis cracteristics of excitation system are analyzed,and the principle of power system stabilizer(PSS)is described,and then studies the phase parameter tuning software of PSS in excitation system based on enggieering applicaion,and adopts Paartice Swarm Optimization(PSO)algorithm.)Optimizing the parameters of the controoller and realizing the opttima parameters can provvde an effective for the design of excitation controller in pratatical engineering.(3)We designed the global fast Terminal sliding mode excitaion control method.The stability of the controller is analyzed by Lyapunov function,and the efficiency of the method is verified by simulation.(4)Super-twisting Sliding Mode Controller(SSMC)excitation controller is designed by using output feedback,which ensures that the controller has terminal voltage regulation function and solves the problem that the controller can't control terminal voltage by using state feedback.The simulation results show that the method has strong global stability and anti-j amming ability,and its performance is better than PSS.