The Research Of Linear Optimal Excitation Control System Based On Fuzzy Control

Synchronous generator excitation control system that is an important part of generator-network harmonization plays a key role to maintain the stability of grid voltage,distribute reactive power reasonably and improve the stability of power system. Practical operation shows that the excitation control system of adopting AVR(automatic voltage regulator) + PSS(power system stabilizer) control strategy which is made up of error feedback and compensating feedback suppresses low frequency oscillation of power system and improve the steady state precision of generator voltage to some extent,but it still exists many shortcomings such as relatively narrow applicable frequency,complicated scene debugging and so on.Excitation control system based on linear optimal control theory which is an important branch of modern control theory has obtained the better control effect than the traditional excitation control system.The weighted matrix of linear optimal excitation control system is usually selected according to the degree of system constraints on state variables under normal operating conditions, so control system has good dynamic quality near the normal operating condition, while the disturbance makes system deviate from the normal operating point, its regulation performance will change bad. Here we use fuzzy controller tracking system operating conditions, fuzzy controller outputs objective feedback gain matrix according to the rule bank built by online interpolation method in later, and then based on sensitivity analysis to comprehensively consider the effect of weight matrix on dynamic performance and the physical realizability of target feedback gain, through Iterative method, weight matrix is obtained. Finally build model of one machine infinite bus power system, simulation results indicate that the optimal weight matrix selection based on fuzzy control makes linear optimal excitation control system show better dynamic quality.