| 摘要 |
PURPOSE:To make it possible to execute the monitor of a suitable control, which is free from an unnecessary protective operation, by making the integral amount of deviation between the set point and the measured value its monitor amount, with regard to the equipment which properly performs the protective operation such as monitor of the flow rate of fuel, etc. of the boiler automatic control system, etc. CONSTITUTION:The upper limited value MH and the lower limited value ML to the flow rate are set in advance, and in case when it has exceeded either of them, the deviation monitor relay 16 gives a set command of the integrator 17. As a result, the integrator 17 starts integration of the deviation between the flow rate of fuel FB and the set point. When these integral values have become equal to the upper limited or lower limited monitor amounts SHM, SLM, the protective operation interlock is operated so that the output is diminished swiftly. In case when the deviation of the flow rate has returned to the allowable value before the integral value becomes equal to SHM or SLM, the integrator 17 is reset. In case of the transient control, it can be prevented that an unnecessary protective operaion operates in case when the control amount is monitored by the protective operation area which is varied as time passes. |
