Feedback Linearization Design Of Coordinated Control System For Ultra-Supercritical Power Unit

The large capacity and high parameters come to be the main developmental direction of China’s fossil power units, it is also to be one of the most effective measures to improve the thermal efficiency of thermal power units. At present, ultra (ultra) supercritical coal-fired power generation will be the main type of fossil power unit in our country, it’s installed gross capacity become top of the world. However, large scale increased the complexity of the operation control of the unit. That is the strong nonlinear coupling characteristics, time-varying and uncertain of the system as it is running from the perspective of control theory. These efficient controls of the unit are very unfavorable, the difficulty of the energy supply and demand balance of boiler-turbine coordinate system. So thorough analysis of the characteristics of large thermal power units and the design of a safe, efficient control scheme based on these characteristics to enhance the coordination of the process of nonlinear system’s ability to adapt to and improve the plant’s economic indicators are of great practical significance.By reading a large number of literature, the thorough analysis on the model of coordinated control system for Ultra-Supercritical power unit in this paper, and choose a 1000 MW Ultra-Supercritical power unit model, which is good for controller design that is gained by mechanism modeling method. Through the model is simplified reasonably, we finally get a simplified nonlinear model which has certain accuracy and is fit for the controller design for coordinated control system.Then the method of exact linearization via state feedback are used and state feedback control law of introduced common nonlinear model is been found; further based on the pseudo linear systems, the boiler-turbine coordinate system based on two degrees of freedom control structure and nonlinear internal model control are constructed respectively. Finally, simulation tests of the state disturbance and comparative analysis are carried out to verify the effectiveness of two different control system.