A Study On Excitation And Fast Valve Coordinated Controller For Synchronous Generators

The stability of electric power system has been being focused for a long time．Toprevent a power system from losing synchronism after sudden fault,researchers have done much work and got many accomplishments．This paper applied the direct feedback linearization(DFL)technique on the power system,a strong nonlinear system．Simulation results by MATLAB proved this method efficiency． Main works and results are as follows: This paper compared some existing methods in excitation control,fast valve control and coordinated control respectively,analyzed the developments and actuality of nonlinear control research in brief,illustrated why ransient stability could be greatly improved by using the fast valve control in chapter 3,indicated the importance of coordinated control farther． This paper introduced the inverse system theory,based on which,discussed the DFL theory,pointed out which had consistency with the inverse theory,expanded the DFL theory combined the idiographic model equations,made which adapt to the model of a single machine-infinite bus power system． This paper referenced abundance articles and educed a set of equations,which could describe the dynamical process of excitation and fast valve control for synchronous generators．In the equations,there were several very important parameters of power system--rotor angle(δ),rotor speed(ω),generator q axis voltage(Eq),transient voltage(E'q),active power(Pe),mechanical input power(Pm),valve opening(μ),generator terminal voltage(Vt),based on the model,nonlinear coordinated controller and terminal voltage optimal controller have been designed by using the expanded DFL theory and LQ optimal control theory．The simulation results showed that the controller could keep power system transiently stable under the effects of a symmetrical 3-phase short circuit fault,which achieved better postfault regulation compared with another two routine methods,one is the proportion excitation controller and proportion fast valve controller,the other is the proportion excitation controller and the optimal fast valve controller,which could exert good performance when met 1ittle disturbance either． This paper brought forward assume of this"nonlinear coordinated controller in both hardware and sotb,vare for an industrial application．...