JPS6021493A - Automatic output regulator for reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an automatic reactor output/adjustment device, and more particularly to a control device capable of responsively and stably controlling the reactor output.

[Background of the invention]

Figure 1 shows the reactor power control system of the BWR nuclear power plant. (The reactor power control system is composed of control rods, a control rod drive system, and a recirculation flow rate control system, but here, it is limited to the recirculation flow rate control system.) Reactor automatic power adjustment device 1-
1 is a digital control device that has a control function and a monitoring function using a microcontroller. Load pattern required in advance (14-1-8-1 method; daytime 14
(time high output, 1 hour output decrease, 8 hours night low output, 1 hour output increase, 12-3-6-3 method, etc.), and the operator selects one of the turns. In particular, automatic operation according to the required load is possible. The reactor automatic power adjustment device 1-1 generates five selected power output patterns as a function of time, and recirculates the difference between the actual generator output and the generator output request value in cooperation with the turbine control device 1-3. The information is transmitted to the flow rate control device 1-2, and the scoop pipe position adjuster 1-6. By changing the speed of the recirculation pump 5 through the M-G set 1-13, the core flow rate is adjusted to change the reactor output, and the generator output is finally adjusted to the output power generated by the reactor automatic power adjustment device. I am trying to follow.

In addition to these functions, it also monitors the reactor core/plant status as well as the functions of the equipment itself, and if there is a malfunction, appropriate measures can be taken such as issuing an alarm or canceling the automatic reactor power adjustment device. That's how it is.

Furthermore, the reactor automatic power adjustment system is equipped with automatic frequency control operation to automate the break-in operation (CPCIOMR operation) to maintain fuel integrity, and to secure the amount of adjusted power that is required from moment to moment. It also has the function of automating (AFC operation).

FIG. 2 shows a control block diagram of the automatic reactor power adjustment device.

As described above, the automatic reactor power adjustment device 1-1 has the following control modes: (1) daily load adjustment, output change mode, (2) PCIOMR mode, and (3) AFC (automatic frequency control) mode.

Each of these modes will be explained. When the daily load adjustment and output change mode is selected by the operator, mode 5W2-7 is ONL.

For the output pattern generated in the target generator output generation section 2-4, the deviation from the generator output 2-2 is calculated, proportional integral calculation is performed, and the difference between the output pattern and the main steam flow rate signal 2-3 corresponding to the reactor output signal is calculated. By taking the deviation, it is converted into equivalent to the reactor output, and a control signal is output to the recirculation flow rate control device 1-2. here,
The reactor automatic power adjustment device 1-1 is for digital control.

The control signal has a pulse limiter 2-11L in terms of pulses and a pulse limiter 2-14f to prevent the pulse from being output easily.

The PCI OMB mode (mode SW2-8) is almost the same, but from the viewpoint of core protection during PCIOMR operation, it is equipped with a rate of change limiter 2-13 in consideration of the 7 fail safe in the case of erroneous control. There is.

Regarding AFc mode (mode SW2-9).

For the target generator output 2-4, the momentary load request command signal 2-1 (equivalent to earth count) sent from the central power supply station in the future is applied to the upper and lower limit limiters 2-5 and the rate of change limiter. 2-
6. This value becomes the target output, and a proportional integral calculation 2-10 performs a calculation to set the reactor output, and the same (2-12) performs a speed required operation amount calculation for the recirculation flow rate control device 1-2.

As described above, the control amount is calculated based on the deviation between the target generator output and the actual generator output, and is output to the recirculation flow rate control device 1-2. As a result, it is known from experience that the time required for feedback to one generator output is about 20 to 30 seconds.

In addition, since this device processes all signals digitally, the minimum operation amount is fixed, and it does not respond to deviations within the dead band.・If the dead band is exceeded, a control signal is issued as the manipulated variable.

Furthermore, the feedback of the main steam flow generator output through the plant is 20 to 3 in response to the issued control signal.
Since it takes about 0 seconds, the control signal will continue to be output during that time.

That is, when a fast response is required (control at a one-second cycle), such as AFC operation, the current control system has the drawback of not being able to follow the response sufficiently. FIG. 3 shows the follow-up characteristics of the generator output during AFC operation.

It can be seen that the generator output follows the target generator output, but it can be seen that the generator output that reaches the vicinity of the target point becomes stable and then hunts.

This is because, as mentioned earlier, the deviation of the generator output within the dead band (10.1% in this device) accumulates due to the integral term of the proportional integral calculation, and the control signal deviates from within 10.1%. This is because it continues to be output until there is feedback from the generator output or the main steam flow rate signal.

[Purpose of the invention]

An object of the present invention is to provide a control device with quick response and stability by adding advance control to an automatic reactor power adjustment device.

[Summary of the invention]

The present invention is an automatic reactor power adjustment system in which a part of the required speed operation amount is fed back during AFC control to perform advance control.

[Embodiments of the invention]

Figure 4 shows a block diagram of an automatic reactor power adjustment system to which the newly invented circuit has been added.

Regarding AFC operation, AFC mode (mode 5W2-9
) is selected, the load request command 2-1 from the central power supply station is superimposed on the target generator output 2-4, and the reactor output setting is calculated based on the deviation from the generator output 2-2. Recirculation flow rate control device 1- from deviation from main steam flow rate 2-3
A speed request signal to 2 is issued. Here, the speed request signal is delayed by the first order 4-1. By adding simple feedback consisting of a gain of 4-2 and a gain of 4-2, it has an advanced control function that takes into account the delay in the main steam flow rate signal. Here, the second delay time constant is set to a value that is equal to or slightly smaller since the delay of the main steam flow rate signal in the plant is approximately 20 seconds, and the gain 4-2 is set as a correction loop,
Although the speed request signal is about 010 to 20, it is not necessary to set it strictly.

By adding this feedback loop, if the control device requires fast response in digital control and the response from the controlled object is slow, adding this correction loop and performing advance control will improve the overall It becomes possible to ensure fast response and stability of the control system.

In addition, with this device, the constant survey of the proportional-integral calculator 2-12 for calculating the speed required manipulated variable conventionally required the effort of using plant simulation test results and survey tests on the actual machine, but with this correction loop, In order to correct the output of the proportional-integral calculator 2-12 without a large delay, it was experimentally found that the required speed operation amount to the recirculation flow rate control device 1-2 is stabilized. This has the effect of considerably reducing the time required for parameter surveys.

FIG. 5 shows the generator output response characteristics of the automatic reactor power adjustment system to which the present invention is added. Compared to Fig. 3, it can be seen that the generator output does not suffer from the pinching phenomenon and a stable output can be obtained.

As described above, by adding a simple correction loop, stable control can be achieved and it can be said that it greatly contributes to improving reliability. In addition, this loop is inexpensive because it requires two additional logics, and there is no problem economically.

〔Effect of the invention〕

According to the present invention, the control performance of the automatic reactor power adjustment device is improved, and it contributes to the improvement of the operating rate, safety, and reliability of nuclear power plants.

[Brief explanation of the drawing]

Figure 1 shows an overview of the reactor power control system, Figure 2,
FIG. 4 is a control block diagram of the automatic reactor output adjustment device, and FIGS. 3 and 5 are diagrams showing the results of a generator output follow-up test of the above device. 1-1... Nuclear reactor automatic power adjustment device, 1-2... Recirculation flow rate control device, 1-3... Turbine control device, 1
-4... Nuclear reactor, 1-5... Recirculation pump, 1-6
... scoop pipe position adjuster, 1-7... water supply pump,
1-8...Adjustment valve, l-9...Nokuino(su valve), 1
-10...Turbine・1-11...Generator・1-1
2...Condensation! Medical examination. 1-13...MG set, 2-1...AFC signal strength-2...generator output, 2-3...main steam flow rate.
2-4...Target generator output generation section, 2-5.2-13
...Upper/lower limit limiter, 2-6.2-14...Change rate color 11 limiter, 2-7...Daily load adjustment, output change mode 8
W-2-8...PCIOMR mode SW, 2-9...
・AFC mode SW, 2-10. 2-12...Proportional integral operation ・2-11...Gain, 4-1...-Next lag circuit, 4-th diagram ■0. ■〆da2 3rd 41st ■3. −ichishi/′−′

Claims (1)

[Claims] 1. In the reactor automatic power adjustment device located in the upper control device of the recirculation flow rate control system, which is one of the reactor power control systems, a first-order lag is added to the output signal by proportional-integral calculation. In the first aspect of the claim, the automatic reactor output adjustment device is characterized in that a feedback signal is added to the plant. An automatic reactor power adjustment device characterized in that it facilitates parameter survey of proportional-integral calculations due to increasing complexity.