| With the development of social economy in our country,the structure of the power grid is becoming more and more complex.To ensure the quality of power and to make the power system safe and stable,it is of great significance to study the excitation system of generators.The excellent excitation system can maintain the generator terminal voltage or the voltage level of the designated point in the system,which can improve the static transient stability of the power system operation,reasonably allocate the reactive power of the hydro generator unit,to provide users with qualified power.The hydroelectric generating set,the core part of the excitation system is the control of its research,the subject proposed to select a superior control of the excitation,or two of them,the three excitation control together,Forming a more superior performance of the composite excitation control.First of all,according to the operation mode of generator and grid,the mathematical model of generator is established.It includes six voltage differential equations,two rotor differential equations,six flux chain algebraic equations and one electromagnetic torque equation.System and grid mathematical model.Secondly,this paper will set up the control unit model of the excitation system.The control mode is to adopt PID control,nonlinear PID control and fuzzy PID control.The emphasis will be on the details of the latter two control modes,and the advantages and disadvantages of several control modes.Finally,under the control of several kinds of excitation,the system parameters are set reasonably,and the Simulink module library in MATLAB is used to reasonably select the simulation objects for simulation.The above excitation control method is used to simulate the generator during full load operation and part load operation.The simulation results of several are compared and analyzed comprehensively.Through simulation,we can draw non-linear PID control,fuzzy PID control methods have the advantages of fast rise,short adjustment time,high pressure regulation accuracy,the robustness is better.However,compared to non-linear PID control,fuzzy PID control hassome improvements in its fastness and stability,and its rise speed and recovery time are relatively superior. |
