【摘要】 火电厂超临界机组结构复杂,过热汽温对象具有大迟延、时变、非线性等特性,常规PID控制难以取得满意的控制效果。在结合常规模糊自整定PID控制器和基于控制历史的模糊控制器的基础上,引入分散推理思想,提出一种基于多模型的过热汽温改进模糊控制方案,设计基于分散推理结构的改进模糊主控制器。在控制过程中,基于不同的工况点设计的控制器可根据系统运行工况的变化进行切换。仿真结果表明,该方案的控制性能明显优于常规PID控制,具有良好的动态调节品质,对工况变化具有较好的适应性。更多还原

【Abstract】 In thermal power plant, the supercritical unit has complicated structure and its superheated steam component has properties of long time delay, time-varying and nonlinearity. Thus, it is difficult to achieve a satisfactory result via the conventional PID control. In this paper, an improved fuzzy control for the superheated steam temperature is designed based on multi-model. Firstly, with the combination of a conventional fuzzy self-tuning PID control and a fuzzy control related to the control history, the decentralized inference is introduced to design an improved fuzzy main controller based on the proposed decentralized inference structure.In the control process, the corresponding controller based on different working conditions can be switched according to the change of load scopes. Finally, a simulation is included. It is shown that the proposed scheme has better control performance than the conventional PID control. A good dynamic regulation quality is realized to adapt the change of operating condition.更多还原