汽轮机控制系统对锅炉汽压对象动态特性的影响

针对目前大型单元火电机组运行中功频调节对锅炉汽压有不稳定因素的现象，分析指出了ＤＥＨ控制系统采用不同的控制方式对锅炉对象动态特性的影响具有本质的区别，ＤＥＨ控制系统为功频调节时机组锅炉汽压对象表现为无自平衡过程，ＤＥＨ控制系统为纯速度调节时为有自平衡过程，并通过仿真给出了燃料扰动和负荷扰动对采用不同ＤＥＨ控制系统的单元火电机组动态特性的影响，最后提出了机组工况不稳定或外干扰频繁时机组的运行方式，这对大型单元火电机组安全运行具有重要的现实意义。

The Influence of a Steam Turbine Control System on the Dynamic Characteristics of Boiler Steam Pressure as a Controlled Object

In view of the presence of destabilizing factors in boiler steam pressure caused by the power-frequency control of current large-sized mono-block thermal power plant units the authors have performed an analysis of the digital electric-hydraulic (DEH) control modes. It is noted that there exists a substantial difference in the influence on the dynamic characteristics of a boiler object when various DEH control modes are put into use. In case the DEH control assumes the form of power-frequency one the boiler steam pressure as a controlled object can be viewed as a self balancing-absent process. When the DEH control functions as a pure speed regulation, the former represents a self-balancing process. By way of simulations the effect of fuel and load perturbations on the dynamic characteristics of a mono-block thermal power plant unit has been determined when different DEH control modes are used. At the end of the paper presented are the operating modes of the mono-block unit under unstable working conditions or in case of a high frequency of outside perturbations. In sum, the paper has provided some hints of highly practical value for ensuring the safe operation of large-sized mono-block thermal power plants.