基于多模型切换的过热汽温广义预测控制

Multi-model switching based GPC and its application to superheated steam temperature systems

火电厂过热汽温对象具有时滞、惯性和参数时变的特性。固定参数常规PID控制器在对象特性发生变化后,控制品质会有所下降。基于多模型切换的过热汽温广义预测控制策略,对若干典型工况点下的固定模型设计子控制器,当系统工况发生变化后,通过有效的切换策略及时准确地切换到最适控制器。提出一种新的平滑切换方法,可有效抑制切换时对象出现的大幅扰动现象。仿真结果验证了该控制策略的有效性。

The superheated steam temperature system in the power plant is a typical time delay, strong inertial and time varying process. Due to these characteristics, the performance of traditional fixed-parameter PID controller tends to deteriorate when the properties of the process change. A new multi-model switching based generalized predictive control （GPC） strategy was presented. A set of linear models was developed according to different loads, and the controllers associated with each model were designed. By an effective switching strategy, the appropriate controller could be selected for different working conditions. A new smooth switching method which can restrain the vibration in the course of switching effectively was also proposed. Simulation results proved the control strategy effective.