联合循环电厂余热锅炉的监督预测控制策略

Supervisory Predictive Control of Boiler in Combined Cycle Power Plant

联合循环电厂中余热锅炉的主要动态特性包括非线性、时滞和不确定性,采用传统控制方法难以实施有效控制。文中所采用的监督预测控制是一种综合的优化控制策略,以设定点优化为核心,具有监督层和调节层的双层控制结构,通过监督层动态优化目标函数,来完成对给定的调节层提供最优的设定点。该算法具有设计简单、易于实现的优点。文中给出了监督预测控制算法的详细推导过程,并以余热锅炉的主汽压对象为例,在不同工况下进行了仿真研究和实时控制,同时与广义预测控制、传统PID控制做比较,仿真结果表明,监督预测控制具有良好的控制效果和跟踪能力。

The major dynamics of the heat recover steam generator in combined cycle power plant include nonlinearities behavior, time delays, and uncertainties. Traditional control strategy could not offer satisfactory result. The supervisory predictive control was based on the set-point optimization method. It consists of a two-level control diagram. The supervisory level dynamically optimizes a general objective function to determine the optimal set-point for a given regulatory level, which is easy to realize. The algorithm of the supervisory predictive control was deduced in detail, and used to control the steam boiler system under different load conditions. Comparisons with generalized predictive control and conventional PID approaches were made. Simulation result shows excellent tracking results.