Study On Excitation Control Strategy For Power System Taking Into Random Disturbance

In this paper, we carry out single infinite machine bus system and four-machinetwo-area of synchronous generator excitation system as research object, aiming at thepower system has nonlinear, uncertain disturbance, nonlinear robust controller forgenerator excitation system is designed. Specific contents are as follows:Aiming at differential geometry for accurate feedback linearization requires a lotof coordinate transformation, the computational complexity and the power system hasnonlinear，model error, uncertain disturbances, Combined with DFL(direct feedbacklinearization) and the nonlinear robust control theory, an excitation control method isproposed. It introduces the terminal voltage feedback of generator to control rules,therefore it solves the problem of terminal voltage deviating. Simulation results showthat the rule can not only improve characteristic of terminal voltage, stability of thegenerator but also can restrain effectively various disturbances.Aiming at the power system has nonlinear, uncertain disturbance, Combinedwith LQR (linear quadratic optimal) and integral sliding mode, a multi-objectiveoptimal sliding mode excitation robust control method is proposed. ESO (extendedstate observer) is applied to estimate and compensate uncertainties in real time, andthe linearization come true. An optimal sliding surface was constructed such that thesystem exhibited global robustness to uncertainties and the ideal sliding modedynamics as the same as that of the optimal LQR for the nominal system. Simulationresults of single infinite machine bus system show that it can not only improvestability of voltage power angle, but can also perform good robustness to variousdisturbances.Aiming at the multi-machine power system has nonlinear, uncertain disturbances;combined with linear quadratic optimal and integral sliding mode, a robust optimalsliding mode excitation controller is designed. The nonlinear extended state observeris applied to estimate and compensate uncertainties in real time, and the linearization come true. The integral sliding mode control was adopted to enhance the robustnessof traditional optimal control law. At last, optimal sliding mode robust controller forfour-machine two-area of synchronous generator excitation system. Simulationresults show that the rule can not only improve stability of voltage power angle, butcan also perform good robustness to various disturbances.