基于模型补偿与切换的锅炉过热汽温控制

为了减小锅炉过热汽温惰性区对象和锅炉负荷变化对汽温调节过程的影响,采用在惰性区对象上并联某-负荷的惰性区对象模型和模型静态增益环节的方法,并根据汽温实际值与模型输出值的偏差大小在汽温实际值和模型输出值之间进行切换,当偏差大于限值时切向汽温实际值,偏差小于限值时切向模型输出值,以此构成单回路固定参数PI控制系统.仿真结果表明,此控制系统可以适应不同负荷的汽温控制,控制品质要优于常规的固定参数PID串级控制系统.

Control of superheated steam temperature based on model compensation and switch

Presents a novel single loop fixed PI control strategy for compensating the high order and load dependent dynamics of the inert section of the super-heater. The dynamic model of inert section for a load and the steady-state gain of the model were in parallel with the plant of the inert section. A switch was used for switching between the output of the super-heater plant and that of the dynamic model, according to the deviation between the output of the super-heater plant and that of the dynamic model. When the (deviation) was larger than the bound, the switch connected to the output of the super-heater plant. Otherwise, the switch connected to the output of the dynamic mode. Simulation results show that this control system is efficient over a wide operation range, and has better performance than the conventional cascade control system.