The Study Of Main Steam Valve Control Of Multi-machine Power System Based On The Adaptive Dynamic Surface Algorithm

With the increasing use of electricity and the increasing complexity of grid structure, the stability problems of power system is becoming more and more serious. So it is necessary to design an advanced control system to improve the stability and dynamic quality of power system.Among the many factors that can improve the stability of power system, the steam valve control has a great significance to improve the stability level of power system, it can not only improve the power system stability with large disturbance, small disturbance and low frequency oscillation, but also can improve the transient response performance of the system. For these reasons, the thesis pays attention to the nonlinear robust control for main steam valve of multi-machine power system. Based on the Lyapunov theory, the nonlinear controller for steam valve is designed by the combination of adaptive dynamic surface and RBF neural network. The main work is as follows:1. The main methods of power system stability control are studied, such as mapping linearization method, Lyapunov direct method, variable structure control and backstepping control and so on.2. In the case of uncertain parameters and coupling terms existence in the multi-machine power system model, the controller for steam vale is designed by the combination of adaptive dynamic surface and RBF neural network. The controller is designed based on the introduction of tracking error conversion function and performance indicators function.3. In the case of the presence of time delay in the interconnections, we designed an adaptive dynamic controller with the L∞ performance by combing the method of adaptive dynamic surface with the RBF neural network. Instead of using the Krasovskii function, we deal with the unknown delay nonlinear term through the finite covering lemma together with the NNs approximators and the L∞ performance of the tracking error can be achieved by introducing the initializing technique.In summary, this paper has designed the adaptive dynamic controller for steam valve of multi-machine power system. The controller is robust to the uncertainty of the system and it can guarantee the performance of the system tracking error. Stability analysis proved that the proposed design scheme can make the system uniformly ultimately bounded and simulation results show the effectiveness of the proposed control scheme.