Design Method Of Wind Turbine Supervisory Control System Based On The Theory Of Discrete Event Systems

With the rapid development of wind power, some new and improved technologies to be used to improve performance of the hardware devices and control system of wind turbine. As the core of wind turbine, control system is the center of all operating data and control commands. However, there are quite a number of states and data when the wind turbine in operation, and may be abnormal due to the impact of external or itself factors at any time. If one subsystem is abnormal and failed to timely treatment, it may lead to other subsystems in abnormal operation, this will seriously affect the normal operation of the whole wind turbine. Therefore, how to improve the performance of wind turbine control system plays an important role in improving the stability performance of overall wind turbine.For the above mentioned problems, this paper proposed a design method of wind turbine control system based on discrete event system (DES) theory. Considering its operation processes conform to the evolution of states and events in DES, states jumped by the trigger of input events, and one state jumped to different states by the trigger of different events. Therefore, use the automata modeling method of DES theory to establish the model of wind turbine subsystems’ operation processes, analyze the operation process of each subsystem, and define all states and trigger events in the operation processes, it can get the system automata models according to the mapping relations between the states and events, then design the automatic control program of each subsystem through the models. When in operation, the subsystem automata decided the next state according to the current state and the events(control commands/system parameters) that occur in the current state, so as to realize the automatic control subsystems. At the same time, the operation states of subsystems are controlled by the supervisory system, so, according to the relationships between each subsystem, using the DES supervisory theory to design the wind power supervisory system based on event feedback control method, through supervise the events of subsystems and then send the different control commands, so as to realize the control of states jmp between the subsystems and make each link of wind turbine in the sequence of operation.In order to verify the effectiveness and feasibility of the supervisory system, it used Stateflow software of MATLAB to do the simulation analysis in this paper. Simulation results show that the wind turbine supervisory control system designed by using DES theory can effectively supervise the operation states of the wind turbine and achieved the expected effect; Through the supervisory system to supervise the operation states of subsystems, it can avoid a link abnormal which caused the abnormal operation of entire wind turbine; Besides, the design method by using DES theory has realized modular design process of control system, it can improve the efficiency of design control procedure and increase readability, and has a certain theoretical and practice significance in applying to the design of other control systems.