Study On The Control Of Superheated Steam Temperature In Thermal Power Units

In the process of power generation power plant, superheated steam temperature has the characteristics of high temperature and high pressure. It is the highest temperature in the refrigerant boiler steam water system. As the main parameters in the thermal power generating units, measurement and control of the superheated steam temperature plays an important role in the safe and economical operation of the power plant. Superheater is a multi volume and delay relatively large inertia link. The disturbance factors of the superheated steam temperature are much more, and each of the factors affect anothers. Under the action of various disturbance factors, the dynamic relationship of the superheated steam temperature with time is different, which increases the complexity of the superheated steam temperature control system. The research work of this paper is mainly based on sliding mode variable structure control in power plant superheated steam temperature control system in the application.First of all, the design and application of sliding mode variable structure control is studied, and a new integral sliding mode variable structure controller is proposed, and introduces the integral sliding mode variable structure control switching surface a, auxiliary output Riemann zeta function ζ, equivalent control law ueg and switching control design method of law usw. To verify the existence of the sliding surface by using Lee Yap Andrianof function.Secondly, on the basis of analyzing the meaning of the superheated steam temperature control, superheated steam temperature controlled object characteristics (including the static characteristic and dynamic characteristic), in this paper, the SIMULINK dynamic simulation software of Matlab is used to construct the structure model of 300MW superheated steam temperature control system using cascade controller and integral sliding mode variable structure controller.Finally, the control effects of the two control systems are analyzed and compared. Theoretical results show that based on integral sliding mode variable structure control of superheated steam temperature control system has good dynamic and static characteristics, and conventional steam temperature cascade control system is compared with the system of anti-interference ability and robustness has been greatly improved.