Coordinated Control Of Excitation And Steam-valving System For Generator Set

Power system is composed of power generation, power substation, power transmission, power distribution, power consumption and so on, which includes power production and power consumption. Recently, with the rapid development of the economy and the continuous progress of science and technology, people’s demand for electricity is increasing, and the development of the power industry has received more and more people’s attention. At present, with the gradual formation of the power grid which has the characteristics of ultra-high voltage and large capacity, the demand about the stability and reliability of power system are also increasing, so a series of new requirements are put forward for the control system. The methods of power system stability control include the control of excitation and valve control, but one means has not achieved the ideal result, therefore, in consideration of the situation, people try to combina two means to control the stability of power system. At present, the coordination control theory is more and more widely used in the nonlinear power system. Therefore, the research on the coordinated control method has been paid more and more attention.In master thesis, people study on stability control of the single machine infinite bus power system. Designing a nonlinear controller based on Lyapunov theory and backstepping method. First, selectting one machine infinite bus power system of fourth order mathematical model, and designing a coordination controller which is about excitation system and valve system by backstepping method. The coordination controller includes state constraints. In the design process, a virtual control variable is defined by selecting a function with constraints. On this basis, in order to speed up the transient response speed, people put forward the improved backstepping method, which has been added a K-class function. Due to the properties of monotone non decreasing of K-class function, and after a fault occurs in the system, the controller greatly improves transient response speed of the system, but it is no excessive gain. After that, considering the fact that the actual operation of power system exists various kinds of uncertainties and external disturbances, the adaptive controller and the adaptive robust controller are designed. Finally, it carries on the simulation experiment by MATLAB software, simulation results show that, the controller can not only make the speed of convergence in power system get fast, but also make the system get more stable. The controller have good effect in the estimates of uncertain parameters and the inhibition of external disturbance, and the results verify the method that is effective.