【摘要】 与传统水冷机组相比,空冷机组易受环境因素变化影响,对象特性更为复杂。建立空冷机组负荷-压力对象动态模型,分析其主要参数的变化规律及范围,在此基础上,采用机跟炉和炉跟机两种控制方式,仿真分析负荷-压力工作点、排汽压力、燃料发热量变化对控制系统性能的影响。结果表明:PID控制器具有较好鲁棒性,能够克服机组排汽压力、燃料发热量变化对控制系统的影响;负荷-压力工作点变化造成模型中制粉惯性和迟延、锅炉蓄热系数的变化以及对象自身非线性仍然是影响空冷机组控制品质的主要因素。更多还原

【Abstract】 Compared with traditional water-cooled units,air-cooled units are susceptible to the changes of environmental factors,and,as a result,their object characteristics become more complicated.A load-pressure object dynamic model of the air-cooled units was established,and the variation regularity and range of their main parameters were analyzed.On this basis,by employing two control modes,namely,boiler operation based on turbine control and turbine operation based on boiler control,simulated and analyzed was the influence of the load-pressure operating point,exhaust steam pressure and the change of fuel heat value on the performance of the control system.It has been found that PID (proportional,integral-differential) controllers can boast a relatively good robustness,and can overcome the influence of the change of exhaust steam pressure and fuel heat value of the power unit on the control system.The pulverized-coal milling inertia and time delay as well as the change of boiler heat accumulation coefficient in the model both caused by the change of load-pressure operating point,and the self nonlinearity of an object under study still constitute the main factors influencing the control quality of the air-cooled unit.更多还原