JPH01111104A - Feed-pump turbine controller - Google Patents

Abstract

PURPOSE: To control the speed of a water supply pump smoothly and stably by making a decision that an abnormality has occurred if a speed command signal from a water supply controller or the variation rate thereof exceeds a specified upper limit and keeping the speed command signal at a level prevailing immediately before occurrence of abnormality. CONSTITUTION: When a speed command signal 5 from a water supply controller deviates from a predetermined upper or lower limit, an upper/lower limit comparator 27 functions to output an abnormality detection signal and turns a signal switching means 21 to the side b. When the variation rate of speed command signal 5 exceeds a predetermined upper limit, a variation rate upper limit comparator 30 functions to deliver an abnormality detection signal to the signal switching means 21. The means 21 is turned to the side b and the speed command signal inputted to a control operating unit 24 is held at a level immediately before occurrence of abnormality stored in a signal holding means 25. Speed of a water supply turbine pump 1 is thereby held stably at a level immediately before occurrence of abnormality regardless of the abnormality signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a feed water pump turbine control device, and more particularly to a feed water pump turbine control device suitable for protecting the feed water pump turbine from signal abnormalities in speed command signals. .

[Conventional technology]

The conventional water supply pump turbine control device is disclosed in Japanese Patent Application Laid-Open No. 56-1
As described in Japanese Patent No. 65805, when the turbine speed is below a certain value, the turbine speed is controlled according to a manually adjusted speed setting signal, and when the turbine speed is within a certain range above the above value, the water supply is Control is performed according to a speed command signal given by a control device. and,
If the speed command signal is lost while controlling according to the speed command signal given by the water supply control device, the speed setting will be changed from the speed command signal in order to prevent malfunction of the water supply pump turbine and its adverse effects on the plant. I am trying to switch to a signal. Further, in order to prevent sudden changes in the speed control signal during this switching, a tracking circuit is provided, and the tracking circuit maintains the speed setting signal at a value approximately equal to the speed command signal.

[Problem that the invention seeks to solve]

However, according to the above-mentioned conventional technology, this is a safety measure only when the speed command signal is lost, and no consideration is given to cases where the speed command signal exceeds a certain upper limit or changes suddenly. Because of this, there was a problem that the water supply pump turbine would malfunction in the event of such an abnormality, which would have a negative impact on the plant.

In addition, the above conventional technology has a tracking circuit as a countermeasure in case the speed command signal is lost, but the method of setting the speed setting signal and the switching operation with the speed command signal are complicated, etc. No consideration was given to performance and maintainability.

An object of the present invention is to solve the above-mentioned conventional problems, in other words, to smoothly and stably control the speed of a water pump turbine even if an abnormality such as an abnormally high value or sudden change in the speed command signal occurs. The object of the present invention is to provide a water supply pump turbine control device that can perform the following functions.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a water supply pump that controls the speed of the water pump by controlling a steam control valve based on a speed command signal given from a supply pump control device. In the turbine control device, an abnormality detection signal is output when the index command signal exceeds a certain upper limit value, and an abnormality is detected when the absolute value of the rate of change of the speed command signal exceeds a certain upper limit value. signal abnormality detection means for outputting a signal; signal holding means for always holding the current value of the speed command signal; and signal switching for switching the speed command signal to the signal held in the signal holding means in response to the abnormality detection signal. It is characterized by having a means.

[Effect]

With this configuration, the signal abnormality detection means determines whether the speed command signal exceeds its normal upper limit value or the absolute value of the rate of change exceeds the upper limit value, so it is possible to detect signal abnormalities other than signal loss. can do. When the signal abnormality detection means determines that there is an abnormality, the signal switching means is activated and the speed command signal is switched to the signal held in the signal holding means. As a result, the speed command signal is held at the value immediately before the abnormality was determined, and the speed of the water pump turbine is maintained smoothly and stably without exceeding the upper limit value or undergoing sudden speed changes. will be controlled by.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 2 shows the overall configuration of an embodiment to which the present invention is applied, in which a water supply pump turbine 1 drives a water supply pump 2 directly connected to the same shaft by steam supplied from a steam generator (not shown). It is something. Feedwater pump turbine 1st rotational speed Speed command signal 5 associated with the requested value of feedwater flow rate for the steam generator outputted from the feedwater control device 4 or speed operation signal 7 set by the operator outputted from the operation panel 6 It is designed to be controlled based on These signals 5 and 7 are input to the turbine control device 8, and the turbine control device 8 controls the feed water pump turbine 1 based on the speed operation signal 7 when the speed is below a certain speed, and exceeds that speed. In a certain range (hereinafter referred to as automatic mode speed range), automatic control is performed based on the speed command signal 5. The turbine control device 8 generates a speed control signal based on the deviation between the speed signal 11 detected by the gear 9 provided at the shaft end of the water supply pump turbine 1 and the rotation detector 10 and the speed command signal 5 or the speed operation signal 7. 12 is outputted to a control valve operating device 13, thereby adjusting the steam control valve 3 and controlling the speed of the feed water pump turbine 1 to a value based on the speed command signal 5 or the speed operation signal 7. .

Here, the detailed configuration of the turbine control device 8 will be explained based on FIG. 1. The speed command signal 5 is transmitted to the signal switching means 21. Automatic manual switching means 22. The signal is input to the control calculator 24 via the rate of change limiter 23. Control calculator 2
4 is the input signal and the feedback speed signal 1
A speed control signal 12 is generated based on the deviation of 1 and is output to a control valve operating device 13. The speed command signal 5 is inputted to one switching contact a of the signal switching means 21, and the holding signal outputted from the signal holding means 25 is inputted to the other switching contact a. This signal holding means 25 always holds the content of the signal of the common contact C of the signal switching means 21.

On the other hand, the speed command signal 5 is input to the signal abnormality detection means 26. The input speed command signal 5 is sent to the upper and lower limit comparator 2
7, where it is compared with predetermined upper and lower limits, and when these are exceeded, an abnormality detection signal is output to the OR circuit 28. The speed command signal 5 is also guided to a rate-of-change calculator 29, where the rate of change of the signal is determined. The rate of change thus obtained is led to the rate of change upper limit comparator 30, where it is compared with a preset upper limit of the absolute value of the rate of change, and if it exceeds this, it is determined to be abnormal and an abnormality detection signal is sent. is outputted to the signal switching means 21 via the OR circuit 28.

On the other hand, the speed operation signal 7 input from the operation panel 6 is
It is input to the switching contact of the automatic manual switching means 22 via the speed setting means 31. The common contact C of this switching means 22 is connected to the signal holding means 33 via the switching device 32, and the output of this signal holding means 33 is connected to the speed setting means 31.
has been entered.

The automatic manual switching means 22 is configured to switch to the contact a side in the automatic mode speed range of the water supply pump turbine 1 described above, and to the contact a side when the speed is below that speed range.

Further, the switch 32 is opened and closed as necessary, and the signal at the output terminal C of the automatic manual switching means 22 is inputted to the signal holding means 33 as a tracking signal. Also,
The speed setting means 31 includes an integrating circuit,
The difference between the tracking signal inputted from the signal holding means 33 and the speed operation signal 7 is integrated and outputted as a speed setting signal 34 to the automatic manual switching means 22.

The operation of the embodiment configured as described above will be described next. Speed increase control in a normal state is controlled by a speed operation signal 7 given by an operator from an operation panel. In this case, the automatic manual switching means 22 is switched to the b side, and the speed setting signal 34 is input to the control calculator 24 via the rate of change limiter 23. Therefore, the speed of the water pump turbine 1 is determined by the speed control signal 7 on the control panel 6.
The speed increase will be controlled based on the following. In this case, if the switching device 32 is closed, the speed setting signal 34 will be tracked via the signal holding means 33, so even if a sudden operation is performed by mistake, the speed setting signal 34 will remain unchanged due to the action of the speed setting means 31. 34 is suppressed, and the speed of the water supply pump turbine 1 is increased smoothly and stably.

When the speed of the water supply pump turbine 1 increases in this manner and reaches the automatic mode speed range, the automatic manual switching means 22 is switched to the a side. As a result, the water supply control device 4
A speed command signal outputted from the control unit 24 is inputted to the control calculator 24 via the signal switching means 21, the automatic manual switching means 22, and the rate of change limiter 23. Therefore, in the automatic mode speed range, the speed signal 1 to be fed back
The speed control signal 12 is determined so that the deviation between the speed command signal 5 and the speed command signal 5 is O, and the feed water pump turbine 1 is controlled to operate at a rotation speed commensurate with the amount of water to be fed requested from the steam generator. At this time, the contents of the signal holding means 25 are constantly updated based on the contents of the speed command signal 5.

Next, the operation when an abnormality occurs in the speed command signal 5 for some reason will be explained. When the value of the speed command signal 5 increases or decreases beyond a predetermined upper or lower limit value, the upper and lower limit comparator 27 operates and outputs an abnormality detection signal, thereby causing the signal switching means 21 to switch to b.
can be switched to the side. Further, when the absolute value of the rate of change of the speed command signal 5 exceeds a predetermined upper limit value, the rate of change upper limit comparator 30 operates and an abnormality detection signal is output to the signal switching means 21. Note that the rate of change is positive.

Two types of upper limit values may be set depending on the negative value. As a result, the signal switching means 21 switches to the b side, and the speed command signal input to the control calculator 24 is held at the speed command signal stored in the signal holding means 25 immediately before the abnormality. Therefore, the speed of the water supply pump turbine 1 is not affected by the abnormality signal, and is stably maintained at the speed corresponding to the speed command signal immediately before the abnormality. When manually operating the water supply pump turbine l in an abnormal situation, the automatic manual switching means 22 is set to b.
At this time, the switch 32 is closed and the signal holding means 33 is activated by the speed command signal immediately before switching of the automatic manual switching means 22.
By tracking the speed setting signal 34 via the speed setting means 31, it is possible to suppress sudden changes in the signal due to switching of the automatic manual switching means 22.

Note that the change rate limiter 23 suppresses changes in the signal input to the control calculator 24 even if the input speed command signal or speed setting signal suddenly changes. It operates to absorb sudden changes in the signal when the switching means 22 is operated.

As described above, according to this embodiment, even if an abnormality occurs such as the speed command signal becoming abnormally high or changing rapidly due to an abnormality in the water supply control device, etc., the speed command signal can be smoothly and stably controlled. The advantage is that the speed of the water pump turbine can be controlled.

Further, according to this embodiment, since a tracking circuit as in the conventional example is not required, the configuration can be simplified and reliability and maintainability can be improved.

Further, according to this embodiment, in the event of an abnormality, speed control is continued by the holding signal held in the signal holding means 25, so the speed setting signal 34 is not necessarily tracked to the speed command signal. Therefore, the speed control signal 7 on the operation panel 6 can be set in advance to a value that takes into consideration the protection of the water pump turbine 1 or the plant, and if an abnormality occurs in the speed command signal, It is sufficient to simply switch the automatic manual switching means 22, which has the effect of reducing the burden on the operator in an emergency and preventing erroneous operations by the operator.

〔Effect of the invention〕

As explained above, according to the present invention, an abnormality is determined when the speed command signal given from the water supply control device exceeds a certain upper limit or when the absolute value of its rate of change exceeds a certain upper limit. Based on this, the speed command signal is held immediately before the abnormality, so even if an abnormality occurs in the speed command signal, the speed of the water supply pump can be controlled smoothly and stably. This has the effect of preventing malfunction of the water pump turbine and protecting the plant.

[Brief explanation of the drawing]

FIG. 1 is a detailed view of a main part of an embodiment of the present invention, and FIG. 2 is an overall configuration diagram of an embodiment of the present invention. 4... Water supply control device, 5... Speed command signal, 6...
- Operation panel, 7... Speed operation signal, 8... Turbine control device, 12... Speed control signal, 21... Signal switching means, 25... Signal holding means, 26... Abnormal signal Detection means, 27... Upper and lower limit comparator, 29... Rate of change calculator, 3°... Rate of change upper limit comparator.

Claims (1)

[Claims] 1. In a feed water pump turbine control device that controls the speed of a feed water pump by controlling a steam regulating valve based on a speed command signal given from a feed water pump control device, when the speed command signal exceeds a certain upper limit value. A signal abnormality detection means that outputs an abnormality detection signal and also outputs an abnormality detection signal when the absolute value of the rate of change of the speed command signal exceeds a certain upper limit value, and always maintains the current value of the speed command signal. 1. A water supply pump turbine control device comprising: a signal holding means for controlling the abnormality detection signal; and a signal switching means for switching the speed command signal to a signal held in the signal holding means in response to the abnormality detection signal.