The Nonlinear Coordinated Control For SVC And Generator Excitation And Steam Valve

In order to make power generation and transmission more efficient, economical and convenient, interconnection technology of power system is developing quite rapidly, and a variety of new equipments have been put into practice, but it also cause many new problems, such as increasing the scale and complexity of power system, brings many dynamic problems which may threaten the safety, economical and stable operation of power system, it proposes higher and more stringent requirements to the system.In terms of control requirement, a single controller is designed for a particular target, but we need to consider more factors for the growing complexity of power system. But some research shows that without considering the connection and interaction of other relevant parts the coordination control strategy cannot improve the performance of system, and even cause the deterioration of system performance; so it is very important to reduce the interaction between different controllers.In this paper, it discusses the nonlinear coordinated control of SVC and generator excitation and steam valve based on Backstepping method for single machine infinite bus system with SVC. Firstly, integrate integral Backstepping method and terminal sliding mode theory, and virtual error integral is introduced into Lyapunov function to eliminate the residual error., so the coordinated control of SVC and steam turbine-generator for single-machine infinite bus power system is designed. Secondly, considering the input constraints, the switching control law is introduced to solve the input constraints problem. a switching coordinated control of SVC and steam turbine-generator is designed based on the Backstepping method. Then considering the influence of internal and external disturbances, a nonlinear large disturbance attenuation coordinate control scheme is investigated based on the adaptive Backstepping and Minimax method for the single-machine infinite-bus system with steam valve and SVC. he Minimax method does not need to estimate the upper bound of the disturbance and the inequality scaling, so it can reduce the conservativeness of the disturbance treatment effectively and makes the system more quickly suppression the interference and return to equilibrium more quickly, so it can ensure the good robustness and the insensitivity to large disturbances. Finally, the adaptive control law is introduced to solve the uncertainty of damping coefficient. The simulation results show that the effectiveness of the designed controller of SVC and generator excitation and steam valve.