| 摘要 |
<p>PURPOSE:To diagnose a switching valve even in an unattended power plant by giving a test signal for a prescribed degree of opening of the switching valve after the output from a timer at the time of detecting that the actual degree of opening of the switching valve is '0'. CONSTITUTION:When the water level goes to a prescribed level or lower, a discharge valve actual opening degree return signal R corresponds to complete closing. This state is detected by an actual opening degree detector 24, and the detection output is supplied to an AND gate 25 and a timer 26. When this state continues for a time T1 or longer, the output is given from the timer 26 to a timer 28 through a timer 27 and the gate 25 and is supplied to a relay 22. Then a normally open contact 222 is closed nd the test opening degree is supplied to an adder 21. In such a state, a discharge valve opening degree command value P is issued to the adder 21 and is added there, and the addition output is is supplied to a comparator 23. An output corresponding to the test opening degree is outputted as the deviation from the comparator 23 and is outputted as a discharge valve opening degree command through a multiplier 29.</p> |
