Design Of STATCOM Nonlinear Control For Multi-machine Power Systems With Output Constraints

Nowadays,China's economic situation is actively improving,the development of China's economy is getting faster and faster,and the power consumption is also increasing.Therefore,the scale and structure of the power grid is becoming slowly complicated.Based on this situation,the power supply is guaranteed.The stability of the power system is pretty significant.Static synchronous compensator is a kind of FACTS equipment,which is widely used in multi-machine power systems.Simulation analysis verifies the effectiveness of the method.It is worth to study whether it can be kept stable under constraints.The transient stability of multi-machine power systems with STATCOM is studied.Backstepping method,Lyapunov method and fuzzy control were used to verify its transient stability.The specific contents of the study are as follows:(1)Assuming that the power system is in an ideal operating state,the output of the speed difference will have an allowable change range during the normal operation of the power system.The power system is determined according to whether the change in the speed difference is within the range that meets the requirements stability.In the design of controller,the backstepping method and the Lyapunov function method are mainly used.In order to make the stability effect better,the fluctuation range of the speed difference becomes smaller,so that the K-type function is introduced,and the sliding mode control is used to design the improved controller.(2)The controller is designed to ensure the transient stability of the system in order to accurately measure the damping coefficient in the multi-machine power system.The backstepping method,Lyapunov function method,and adaptive control method are used to design the STATCOM controller.Well,the fluctuation range of the speed difference is smaller,and the time to restore stability is shorter.The improved backstepping method and sliding mode control method are applied to design an optimized constrained sliding mode adaptive STATCOM controller.(3)In order to solve the problem that the damping coefficient can't be measured accurately and the influence of external disturbance,the design method of the controller is simplified.In this design,in addition to the above control methods,the direct fuzzy control method is also introduced to design a nonlinear fuzzy adaptive controller to verify whether the transient stability has achieved good results.On this basis,the K function is introduced to further improve,and then the improved nonlinear fuzzy adaptive controller is designed to achieve better transient stability.