600MW超临界机组协调控制系统模型优化研究

Research on the optimization model of coordinated control system for 600MW supercritical unit

超临界机组多变量耦合、强非线性、不确定性等特点给控制系统设计及调试带来一定的困难,而研究超临界机组主要被调量的动态特性并建立结构简单的协调模型可很好地解决以上问题。该文将机理建模与试验建模进行结合,对结构复杂的协调控制模型进行优化,针对某600MW超临界机组,在机理分析模型结构的基础上,根据模型之间的共性,对模型结构进行简化。通过现场试验获取主要调节量即燃料量、给水量、阀门开度扰动下的动态特性,采用改进的粒子群算法辨识获得600MW超临界机组三输入三输出的数学模型,该模型动态特性与理论分析保持一致,验证模型可靠性。此外,模型结构简单且能很好地反映超临界机组的动态特性,可为进一步研究超临界机组及控制器的设计提供参考。

Supercritical unit has the characteristics of multivariable couping, strong nonlinearity and uncertainty, which brings difficulties to the design and debugging of the control system. Research on the dynamic characteristic of main regulated variable and building of the simply-structured coordinated control model can be helpful to resolve these problems. The paper combines the mechanism modeling with experimental modeling to optimize the complex structure of the coordinated control model, and simplifies the model structure for a 600MW supercritical power unit based on mechanism analysis on its structure and the commonality between models. Through field test, dynamic characteristics of 600MW supercritical unit under the manipulating variable such as fuel quantity, feed water quantity and valve opening are obtained, and then a mathematic model with three-input and three-output is attained by identification with improved particle swarm optimization. The dynamic characteristics of the achieved model conform with the theoretical analysis, so the model's reliability is validated. Besides, the model has simple structure and good dynamic performance, which provides references for the futher study of supercritical units and the design of controller.