过热蒸汽温度系统的串级DMC-PID控制

Cascade DMC-PID Control of Superheated Steam Temperature System

过热蒸汽温度系统的控制效果对火电机组运行的安全性、稳定性和经济性有着重要影响。其被控对象的大迟延、大惯性、多扰动以及时变等特点,令外回路传统PID控制方法难以取得令人满意的控制效果。本文采用传统过热蒸汽温度控制系统的串级结构,充分利用其内回路能快速消除扰动、提高系统工作频率的优点,在保留内回路PID控制器的前提下,进行了外回路DMC控制器设计。仿真研究表明串级DMC-PID控制相较于串级PID-PID控制具有更好的给定值跟随能力和抗干扰能力。

The control effect of the superheated steam temperature system has an important influence on the safety, stability and economy of the operation of the thermal power unit. The large delay, large inertia, multi-perturbation, and time-varying characteristics of the controlled object make it difficult to achieve a satisfactory control effect of the traditional PID control method of the outer loop. This paper adopts the cascade structure of the traditional superheated steam temperature control system, makes full use of its internal loop can quickly eliminate the disturbance, improve the system operating frequency advantages, while maintaining the internal loop PID controller under the premise of the external loop DMC controller design. Simulation studies show that the cascade DMC-PID control has better setpoint following ability and anti-jamming capability than the cascade PID-PID control.