| 摘要 |
This invention relates to electrical engineering, and it can be used to produce invariably stable pressure steam in the steam boilers for utilization in electrical and heat cogeneration plants and in products thermal processing technologies. The aim of the invention is to guarantee high stability of steam pressure in the steam boiler and in the steam consumption line regardless of steam expenditure dynamics, applying invariant control principle of steam boiler power unit control with in time preemptive response to steam supply disturbance. In the proposed invariant control system (Fig.1) the control impact Q on steam boiler (1) is formed in furnace (11) through the fuel burner (10) with air and fuel valves (8, 9), which throughput is regulated with servomechanism (7) by varying feed voltage and frequency by frequency converter (6), controlled with PID controller (4). The steam pressure of the steam boiler, measured with the pressure transducer (2), is transformed into electric signal Up, which is transmitted to the input of the first differential scheme (3). The differential scheme (3) forms the difference of the reference signal Upnom and of the input signal Up, which is transmitted to input of the PID controller (4). The output signal of the PID controller - UPID is connected to adder (5) and is corrected by the output signal ±Uk of the steam supply disturbance compensation controller (14). An input signal ±?Uq of the compensation controller (14) is formed by the second differential scheme (13) as a difference of reference signal Uqnom and of steam consumption flow signal Uq, measured with steam consumption flow transducer (12). |
