The Research Of Quadratic Performance Index In Generator Speed Governing Optimization Control

Generator speed optimization control is the key problem of power system stability control, while trying to all sorts of control theory are applied to generator speed as regulation control, but in reality, general still use the traditional control theory (such frequency domain analysis) and control methods (such as PID).It is the main problem that must be predetermined control target (namely the objective function)when use the the modern control theory, the control effect not only depends on the control method, but also often depends more on control goals. And because of the complexity of the machine power system,it is not easy to determine in advance of the change of state after the system disturbance track and the new stable equilibrium, thus it is difficult to determine each machine machine control goals. Therefore,it is is particularly to important analysis of the objective function.First introduced the steam turbine and the governor of several common model, this paper expounds the basic design method of valve linear and nonlinear optimal control (state feedback linearization) and general steps of optimal controller design. Analyzed the quadratic performance indexes for optimal control, points out the contradiction with the actual power system stability control:performance index in setting goals is to return to the state before disturbance stable equilibrium point, and it is is not likely to back to the original stable equilibrium point after the actual power system disturbance.With single and double machine infinite system as an example, the analysis found that in the instantaneity disturbance disappeared, generator state variable (rotor Angle and speed) can go back to the original stable equilibrium point. Using the traditional quadratic performance indexes, in view of the second order and the third order model, are used for the linear and nonlinear optimization valve control, the simulation show that all can achieve good stability control effect. And then analyzes the the relationship between the size of weight coefficient the deviation square state of in performance indexe and control tracks, the simulation found that the bigger weight coefficient of rotor Angle AS1 and speedΔω2 in a certain range, the faster of the rotor Angle and speed state close to the original stable equilibrium point; And the smaller weight coefficient of high pressure cylinder powerΔPmh2 in a certain range, the faster rotor oscillation calm.In the system with no infinite node, by dual machine system as an example, the analysis found that, in the short circuit fault protection movement, generator statevariable (rotor Angle and speed) won’t go back to the original stable equilibrium point.And in this case, the linear and nonlinear optimization control performance indexpoints to the stability of the original still break-even point. The simulation analysisalso found,the bigger coefficient relevant state deviation square in the performanceindex, The more near state of the track meet the original balance, but may more fardeviate from the stable equilibrium point.Therefore, the key is control goal setting when power system stability controlwith modern control theory,and the influence of the weight coefficient in quadraticindex to the amount of state control track. In the paper, based on the research of thetutor, detailing the analysis and simulation analysis, the significance of application intheoretical and practical that the research results to modern control theory in powersystem.