JPH01216006A - Turbine control device - Google Patents

Abstract

PURPOSE:To suppress pressure fluctuation in a reactor vessel by inputting output from a servo amplifier which outputs valve driving signals of steam flow control valves into mutual diagnostic circuits, and suitably controlling opening of the steam flow control valves when abnormality is detected by means of mutual diagnosis. CONSTITUTION:Steam flow control valves 10, 11 are respectively provided to a main steam pipe 1 which extends from a reactor 4 to a turbine 6 and to a by-pass pipe 2 which is branched out from the main steam pipe 1 and extends to a condenser 7. In a device which controls the steam flow control valves 10, 11 according to steam pressure and turbine speed, valve opening signals 115-117 of the respective steam flow control valves 10, 11 are input into mutual diagnostic circuits 118-120 for valve opening of respective operational parts of systems I-III. Valve driving signals 107-109 of the respective systems I-III are input into mutual diagnostic circuits 121-123 for valve driving signals. When abnormality of valve opening and valve driving signal is judged, a valve driving signal responding to a normal system is chosen by change-over logic 110 and output into the steam flow control valves 10, 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The object of the present invention is to provide a turbine control device with triple computing units, and in particular to ensure normal operation of a plant when a component in the turbine control device fails. Involved in turbine control equipment that facilitates continuation.

[Conventional technology]

Conventional turbine control devices are used for thermal and nuclear power generation (IS).
SN0387-1029) No. 317, IX, Control and Automation of Nuclear Plants. As shown in FIG. 3, the purpose of the turbine control bag fi5 is to keep the reactor pressure Pr in the reactor pressure vessel 4 almost constant and at the same time keep the frequency na of the generator 8 directly connected to the turbine 6 constant. Therefore, on the upstream side of the pipe branch point 9 on the main steam pipe 1, the main steam pressure pt ta is equivalent to the reactor pressure Pr.
IIJ to control the opening degrees of the steam flow rate control valve 10 and the steam flow rate control valve 11. Conventionally, in such a control device.

As shown in FIG. 4, for the purpose of continuing plant operation, the calculation units are tripled (system!, system ■, and system III) L, control commands 101 output from these triple calculation units, 102, 103, and triplex steam flow rate control valve opening detector (hereinafter referred to as valve opening detector) 11
Valve opening signals 115, 116 from 2, 113, 114,
The valve drive signals 107, 108, and 109 are obtained by the servo amplifier 104, servo amplifier 10'5 degree servo amplifier 106, and the valve drive signal 111 is selected by the switching logic 110.

The 0 normal switching logic 110 that drives the steam flow rate control valves 10 and 11 is the valve drive signal 111 that is the system! Although the valve drive signal 107 corresponding to
When abnormality No. 5 is detected, the system (2), which is a standby system, or the valve drive signal corresponding to the system (2) is selected. Standby system 2
If both systems are normal, valve drive signal 1 corresponding to system ■
08 corresponds to system ■ if system ■ is abnormal. Select valve drive signal 109. The valve opening mutual diagnosis circuits 118, 119, 120 receive the input valve opening signal 1.
Of the three signals 15, 116, and 117, 115 and 116
The values of 116 and 117 are the same, and the values of 117 and 115 are the same. For example, 115 and 116 do not match, 116 and 117 match, and 117 and When the signal 115 does not match, the valve opening signal 115 is determined to be abnormal. Switching logic 110
In System 1. II.

■If obtained from two or more mutual diagnostic circuits in the calculation unit at the same time, the valve opening signal 115, valve opening signal 112, etc. corresponding to system I will be regarded as abnormal and will not be selected. shall be.

According to this method, if the servo amplifier 104 fails while the valve drive signal 107 is selected as the valve drive signal 111 by the switching logic 110, the valve drive signal 108 is selected by the switching logic 110. The steam flow control valve starts to be driven by the valve drive signal 107 which has become abnormal, and after a certain time delay has elapsed due to the time constant of the valve body, the valve opening is inputted from the valve opening detectors 112, 113, 114. The signal selection time by the switching logic 11G is delayed by the time delay on the valve body side, such that the system I abnormality is detected in the valve opening mutual diagnosis circuits 118, 119, and 120 by the signals 115, 116, and 117. there is a possibility.

[Problem to be solved by the invention]

The above conventional technology does not perform mutual diagnosis of parts generated within the turbine control device, so the turbine control V&[
There was a problem in that even when a component failure occurred inside the valve, the switching logic could not switch to a valve drive signal that corresponds to a normal system until a time delay due to the time constant of the steam flow control valve body elapsed. .

The purpose of this system is to switch to a valve drive signal that corresponds to a normal system without being affected by the time delay due to the time constant of the steam flow control valve body when a component failure occurs in the turbine control device. The aim is to minimize the impact on the plant.

[Means to solve the problem]

The above object is achieved by providing a mutual diagnosis circuit for the valve drive signal, which is the output signal of the servo amplifier, and performing abnormality detection by mutual diagnosis for the valve drive signal as well.

[Effect]

Detecting an abnormality in the valve drive signal, which is the output signal of the servo amplifier, using a mutual diagnostic circuit makes it possible to detect an abnormality before driving the steam flow control valve when a component failure occurs in the turbine control device. Become. Thereby,
The switching logic can select a normal valve drive signal before the steam flow control valve is driven by an abnormal valve drive signal, so the steam flow control valve will not malfunction and will have no impact on the plant. can be minimized.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In this embodiment, the valve opening signals 115, 116, 117 of the steam flow rate control valves 10, 11 are calculated by a system summer calculation section,
System ■Arithmetic unit, System ■Arithmetic unit's valve opening mutual diagnosis circuit 118, 119° 120 is input to detect an abnormality in valve opening by mutual diagnosis, and System I valve drive signal 107, System ■Valve drive Signal 108, system■
The valve drive signal 109 is input to mutual diagnosis circuits 121, 122, and 123 for valve drive signals, and mutual diagnosis of valve signals of each system is performed. As a result, the valve opening degree detector 112.11
3, 114 becomes abnormal, or if the part connecting the valve opening detector to the turbine control device becomes abnormal, mutual diagnosis of the valve opening signals 115, 116, 117 is performed as in the past. The switching logic 110 allows the valve drive signal 111 to more quickly select the valve drive signal corresponding to a normal system. Furthermore, servo amplifier output 10
7, 108, 109 as mutual diagnosis circuit 121 for valve drive signal
, 122, 123 performs abnormality detection through mutual diagnosis, in the event that a component within the turbine control device 1i5 fails, the system is not affected by the time delay due to the time constant of the main bodies of the steam flow rate control valves 10, 11. Switching logic 1
10 makes it possible to select a valve drive signal corresponding to a normal system. For example, the servo amplifier 104°1
05.106 are both normal, and the switching logic 110 uses the valve drive signal 1 corresponding to the system I as the valve drive signal 111.
Assume that 07 is selected. Valve drive signals 107, 10 corresponding to each system are the output of the servo amplifier at this time.
Assume that the value of 8,109 is A. In this control state, it is assumed that the servo amplifier 104 corresponding to system (2) has failed.

Then, the valve drive signal 10 which is the output of the servo amplifier 104
The value of 7 is A±α. At this time, in the valve drive signal mutual diagnosis circuit 121 in the system summer calculation section, the value of the valve drive signal 107 corresponding to system I is A±α, the value of the valve drive signal 108 corresponding to system ■ is A, and the value of valve drive signal 108 corresponding to system ■ is A±α. Since the value of the corresponding valve drive signal 109 is A, it is determined that the servo amplifier 104 is abnormal. Similarly, the system ■
The valve drive signal mutual diagnosis circuit 122 in the calculation section and the system 1 mutual diagnosis circuit 123 for valve drive signals in the calculation section also determine that the servo amplifier 104 is abnormal. At this time, in the switching logic 110, since the servo amplifier 104 is judged to be abnormal by two or more mutual diagnostic circuits at the same time, the valve drive signal 107 corresponding to the system I is switched to the normal system ■ as the valve drive signal 111. Switch to the corresponding valve drive signal 108. As a result, the steam flow rate control valve 10.11 will not be driven by the valve drive signal that has become abnormal.The abnormality detection means using a single circuit is as follows:
In addition to failures of the servo amplifier, this is also effective against abnormalities in the connection between the arithmetic unit and the servo amplifier, and abnormalities in the arithmetic unit.

〔Effect of the invention〕

According to the present invention, in a turbine control device in which arithmetic units are triplexed, by providing a mutual diagnosis circuit for valve drive signals, if mutual diagnosis of valve drive signals is performed, failure of parts in the turbine control device can be prevented. Even if a steam flow control valve occurs, the steam flow control valve can be driven by a valve drive signal corresponding to a normal system without being affected by the time delay due to the time constant of the steam flow control valve body. Even when a failure occurs in a component within the control device, the steam flow rate control valve can be optimally controlled and the impact on the plant can be minimized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a time chart of valve drive signals, FIG. 3 is a system diagram of a nuclear power plant, and FIG. 4 is a conventional block diagram. DESCRIPTION OF SYMBOLS 1... Main steam pipe, 2... Bypass pipe, 4... Atomic container, 5... Turbine control device, 6... Turbine,
7... Condenser, 10... Main steam flow rate control valve, 11...
...Bypass flow rate control valve, 101, 102, 103...
・Control signal, 104.105,106...Servo amplifier, 107°108.109,111...Valve drive signal, 110...Switching logic, 112,113,114
... Valve opening degree detector, 115, 116, 117... Valve opening degree signal. 1st drawing 2nd drawing 3rd drawing 4th

Claims (1)

[Claims] 1. A reactor vessel, a turbine, a main steam pipe that guides steam from the reactor vessel to the turbine, a condenser disposed downstream of the turbine, and a condenser branched from the main steam pipe. Detection of steam flow control valves installed in the main steam pipe and bypass pipe downstream of the branch point, and steam pressure in the piping upstream of the branch point, in a nuclear power plant consisting of a bypass pipe connected to the branch point. a first detection means for detecting the speed of the turbine; a second detection means for detecting the speed of the turbine; and control for adjusting the steam pressure to a predetermined amount by the steam flow rate control valve based on output signals of the first and second detection means. In the turbine control device, the main steam piping and the bypass control device are configured to promptly detect an abnormality in the steam flow rate control valve and to continue plant operation without changing the pressure in the reactor vessel. A turbine control device comprising means for optimally controlling the opening degree of a steam flow rate control valve provided in a pipe.