KR102319798B1 - Auxiliary Water Supply Pump Turbine Control System and Method of Nuclear Power Plant - Google Patents

Abstract

The present technology relates to an auxiliary feed water pump control system and method of a nuclear power plant. A nuclear power plant auxiliary feed water pump turbine control system according to an embodiment of the present technology can improve the problems of the existing mechanical and analog electric auxiliary feed water pump control systems, including a governor valve driving device, a turbine speed sensor unit, and a digital controller. However, there is an advantage in that a nuclear power plant auxiliary feed water pump control system and method can be provided, which can be operated stably and efficiently according to the control method desired by the operator and is easy to maintain.

Description

Auxiliary Water Supply Pump Turbine Control System and Method of Nuclear Power Plant

The present invention relates to a system and method for controlling an auxiliary feed water pump turbine in a nuclear power plant, and more specifically, by implementing a control algorithm for a pump that supplies cooling water in a nuclear reactor, which is the core of a nuclear power plant, using a digital control device, thereby providing rapid response, precision and A nuclear power plant auxiliary feed water pump turbine control system and method for improving reliability and operating a power plant safely and efficiently.

In nuclear power plants, the auxiliary water supply system is a safety-related main system, and in the event of an accident in the normal main water supply system, it is an important facility that removes residual heat from the core until the operation conditions for removing residual heat from nuclear fuel in the nuclear reactor are satisfied. It is an essential facility for normal operation within 72 hours after failure. If the operation of this facility is not possible, it may lead to a major accident if the power plant utilization rate decreases and a fundamental problem occurs due to power generation stop according to the power plant operation technical guide. In general, the control of the auxiliary feed water pump applied to nuclear power plants is operated by a mechanical controller designed as a mechanical mechanism and an analog electric control method controlled by a manual device.

The controller designed with a mechanical mechanism has poor responsiveness and precision, and errors and errors increase due to mechanical wear due to long-term use, and also has a problem that requires a huge cost for maintenance. is vulnerable to loss of function due to component deterioration and failure due to single loop, and it is particularly difficult to secure spare parts due to device discontinuation.

In addition, the aging control system used in nuclear power plants is continuously operating, and it is necessary to verify the correct algorithm and control system in that it is connected to the pump turbine, which is a mechanical device, and its peripheral devices. Therefore, in order to overcome these difficulties, the development of a nuclear power plant auxiliary feedwater pump turbine control system using a digital control device with proven reliability is urgently required.

1. Korean Patent No. 10-1214692

An object of the present invention is to provide a system and method for controlling an auxiliary feedwater pump turbine of a nuclear power plant of a digital control method having high responsiveness, reliability and stability in order to solve the above problems.

In order to achieve the above object, the present invention provides a control system for an auxiliary feed water pump turbine for a nuclear power plant, comprising: a governor valve driving device for controlling an operating speed of the auxiliary feed water pump turbine; a turbine speed sensor unit for measuring the speed of the auxiliary feed water pump turbine using a sensor; and a digital controller that receives a predetermined parameter from a user in a digital control method including a central processing unit and control software, receives the speed of the auxiliary feed water pump turbine from the turbine speed sensor unit, and controls the governor valve driving device; It is characterized in that it includes.

Preferably, it further includes a; operation support device connected to the digital controller through wired/wireless communication to display the status of the auxiliary feed water pump turbine from a distance from the digital controller and input the predetermined parameters.

Preferably, the digital controller controls the flow rate of steam flowing into the auxiliary feed water pump turbine through an actuator through signal conversion in EGR according to the speed control set value input from the user and the speed signal calculated by the speed PID control. is to control

Preferably, the digital controller checks the measured value and the target value of the control target according to the control method desired by the user, and adjusts the response and slope of the control target through the deviation of the measured value and the target value and PID control to control the governor valve driving device to perform the auxiliary feed water pump turbine speed control and load control.

A method for controlling a nuclear power plant auxiliary feed water pump turbine according to another embodiment of the present invention includes: measuring a speed of the auxiliary feed water pump turbine by a turbine speed sensor unit using a sensor; controlling a governor valve driving device by receiving, by a digital controller including a central processing unit and control software, a predetermined parameter from a user and receiving a speed of the auxiliary feed water pump turbine from the turbine speed sensor unit; and adjusting, by the governor valve driving device, the operating speed of the auxiliary feed water pump turbine according to the control of the digital controller.

Preferably, the operation support device connected to the digital controller through wired/wireless communication displays the status of the auxiliary feed water pump turbine from a distance from the digital controller and enables the input of the predetermined parameters. .

Preferably, the step of the digital controller controlling the governor valve driving device comprises: converting a signal from EGR according to a speed control set value input from a user and a speed signal calculated by speed PID control, and then using the actuator through the auxiliary It is to control the flow rate of steam flowing into the feedwater pump turbine.

Preferably, the step of the digital controller controlling the governor valve driving device includes checking the measured value and the target value of the control object according to the control method desired by the user, and controlling the deviation between the measured value and the target value and PID control. The auxiliary feed water pump turbine speed control and load control are performed by controlling the governor valve driving device by adjusting the response and slope to the control target through the control.

According to the present invention as described above, it is possible to operate a nuclear power plant more stably and efficiently by improving the problems of the existing mechanical and analog electric auxiliary feed water pump control systems, and by storing and analyzing operation data, failure prediction analysis and maintenance are easy. There is an advantage in providing a nuclear power plant auxiliary feedwater pump turbine control system and method.

1 shows a block diagram of a nuclear power plant auxiliary feed water pump turbine control system according to the present invention.
2 shows a control schematic diagram of a digital controller according to the present invention;
3 shows a detailed block diagram of a digital controller according to the present invention.
4 shows a main menu screen of a human-machine interface program driven by the driving support device according to the present invention.
5 shows proportional, integral, and differential screens of the human-machine interface program driven by the driving support device according to the present invention.
6 shows an automatic start-up sequence screen of a human-machine interface program driven by the driving support device according to the present invention.
7 is a flowchart illustrating a method for controlling a nuclear power plant auxiliary feed water pump turbine according to another embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them, refer to the embodiments described below in conjunction with the accompanying drawings. It will become clear with reference to examples. Prior to this, it should be noted that, if it is determined that a detailed description of a known function and its configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof is omitted.

1 shows a block diagram of a nuclear power plant auxiliary feed water pump turbine control system according to the present invention.

A nuclear power plant auxiliary feedwater pump turbine control system according to the present invention includes a governor valve driving device 100 , a turbine speed sensor unit 200 , and a digital controller 300 .

The governor valve driving device 100 adjusts the operating speed of the auxiliary feed water pump turbine. The turbine speed sensor unit 200 measures the speed of the auxiliary feed water pump turbine using the sensor.

The digital controller 300 receives a predetermined parameter from a user in a digital control method including a central processing unit and control software, receives the speed of the auxiliary feed water pump turbine from the turbine speed sensor unit, and controls the governor valve driving device. do.

In addition, the nuclear power plant auxiliary feed water pump turbine control system according to the present invention is connected to the digital controller 300 through wired and wireless communication to display the status of the auxiliary feed water pump turbine from a distance from the digital controller 300 and input predetermined parameters. It may be to further include a driving support device 400 that can be.

In addition, the digital controller 300 controls the flow rate of steam flowing into the auxiliary feed water pump turbine through the actuator through signal conversion from EGR according to the speed control set value input from the user and the speed signal calculated by the speed PID control. it could be

In addition, the digital controller 300 checks the measured value and the target value of the control target according to the control method desired by the user, and adjusts the response and inclination of the control target through the deviation of the measured value and the target value and PID control. It may be to control the valve driving device 100 to perform auxiliary feed water pump turbine speed control and load control.

2 shows a control schematic diagram of a digital controller according to the present invention;

2, the digital controller 300 includes a governor speed sensor signal processing unit 20, a field speed signal input unit 21, an MCR (Main Control Room, main control room) speed signal input unit 22, an MCR indicator transmission speed signal. It may be composed of an output unit 23 , an on-site speed indicator transmission signal output unit 24 , a valve request signal output unit 25 , and an electrical overspeed trip output unit 26 .

The central processing unit of the digital controller 300 includes functions such as operation of input/output signals, execution of a control algorithm, and confirmation of system information.

3 shows a detailed block diagram of a digital controller according to the present invention.

3, the digital controller 300 is composed of a speed sensor signal input unit 30, a speed set value increase/decrease setting unit 31, MCR priority control activation and MCR speed set value setting unit 32, the speed set value and the actual It can be configured to send an output signal to the governor valve actuator through proportional, integral, and differential control of the speed deviation.

4 shows a main menu screen of a human-machine interface program driven by the driving support device according to the present invention.

4, it includes an upper menu 40 including menu description and time, and a button-type menu 41 for each sequence and function in the middle of the screen, and can be configured to move to each screen when the menu is clicked. In the lower part, the monitoring unit 42 of the current system state and main variables is included, and the main menu summary button 43 may be included in the lower menu.

Each menu name of the human-machine interface program and the current date and time may be included at the top of the program screen shown in FIG. 4 . The middle menu can be implemented to enable turbine start and control, measurement monitoring, data acquisition processing, PID control, main input/output variable confirmation, real-time alarm confirmation and recall, and movement of the trend menu through the button type of the site-map. The lower status monitoring menu can be implemented to check the status of the current control device in real time and, if necessary, to monitor the driving status of the high pressure turbine and the low pressure turbine. The lower mini bar implements the main menu in the form of a button so that it is possible to move directly to the related menu, and may include a home (main menu) button, data storage, output function, and security function.

5 shows proportional, integral, and differential screens of the human-machine interface program driven by the driving support device according to the present invention.

Referring to FIG. 5 , the digital controller 300 may include actual process values and set values according to the gain values of the proportional, integral or derivative of the main signal set to control the auxiliary feed water pump turbine governor valve, and a menu An upper menu 50 including description and time, a portion 51 for checking the actual value versus the set value of each PID, a monitoring unit 42 for system status and main variables, and a main menu summary button 43 may be included.

Since the digital controller 300 applied to the pump and turbine control system of a nuclear power plant requires a quick response due to the characteristics of the generator, a prior control algorithm and suitable PID control needed for a quick response of the turbine must be applied. Check the measured value (PV) and target value (SP) of the control target such as Speed, EXTR, Auxiliary, and Cascade according to the control method desired by the user, and respond to the control target through the deviation of the measured value and the target value and PID control and by adjusting the inclination, it is possible to enable optimal control.

6 shows an automatic start-up sequence screen of a human-machine interface program driven by the driving support device according to the present invention. The automatic startup sequence screen is a screen used when activating the automatic startup sequence through the program of the digital controller 300 and may be implemented using major parameters among step-by-step parameters set to use the automatic startup sequence.

Referring to FIG. 6 , an upper menu 60 including menu description and time, a setting display unit 61 for each speed section, a monitoring unit 62 for system status and main variables, and a main menu summary button 63 are included. can

The control of the existing auxiliary water pump uses an analog control device, and the speed control standard value is manually operated with a dial-type potentiometer in the field or MCR, and the variable resistance signal is input to the Ramp Generator/Signal Converter, The signal is input to the analog controller and the valve control signal is generated through the turbine speed algorithm included in the controller. Another method, the electric control method, is a control method that receives a speed signal using a separate tachometer, detects the overspeed of the pump, generates a turbine trip signal, and transmits the status to the site and MCR.

In contrast, the digital controller 300 of the present invention develops a software program inside the controller by inputting required parameters, respectively, and sets optimal operating conditions for controlling the pump speed. In addition, the speed signal monitored in real time compares the two signals and the high value is used for final control and electrical or mechanical overspeed protection.

The digital controller 300 is composed of, for example, 30 keypads and an LED display capable of displaying 24 characters on the front side, and can provide convenience of operation and monitoring, and setting of parameters to be used for control through the keypad Input and modification, start and end of pump control system, etc. can be entered directly.

The digital controller 300 may support a mod-bus communication method for communication with other devices. A mod-bus can be one that supports RS-232, RS-422 and RS-485 communication with two separate serial ports. In addition, a dedicated computer communication serial port can be supported through RS-232.

The input/output capacity of the digital controller 300 is, for example, a digital input signal 16 points, a digital output signal 8 points, an analog input 6 points, a speed sensor input signal 2 points, an analog output signal 6 points, an actuator driver output signal 2 points , and each input/output channel can be activated or deactivated in software, making it easy to manage input/output channels.

The digital input/output unit of the digital controller 300 may receive data from the central processing unit and drive the solenoid of the field or transmit the set values of rising and falling speed according to the conditions of the field panel to the central processing unit through the operation switch input. The digital input/output unit may have a response time of 10 to 40 ms for each function.

에서 최대 0.145%, Isolation 입력부의 경우 25

에서 최대 0.186%의 정확도를 가질 수 있다. MCR에서 설정하는 속도 설정치에 대한 Potentiometer 신호를 트랜스미터를 통해 변환된 4 ~ 20mA로 입력 받을 수 있다.The analog input unit of the digital controller 300 may have a resolution of 16 bits within a range of 0 to 25 mA and a response time of 10 to 40 ms for each function. Accuracy is 25 for Non-Isolation inputs

0.145% max at 25 for Isolation input

can have an accuracy of up to 0.186% in The potentiometer signal for the speed set value set by the MCR can be input as 4 ~ 20mA converted through the transmitter.

에서 최대 0.4%의 정확도를 가질 수 있다. MCR에 설치된 지시계 및 현장 판넬에 설치된 지시계에 4 ~ 20mA 출력을 전달할 수 있다.The analog output unit of the digital controller 300 may have a resolution of 10 bits within a range of 0 to 25 mA and a response time of 40 ms. Accuracy is 25

can have an accuracy of up to 0.4% in 4 ~ 20mA output can be delivered to the indicator installed in the MCR and the indicator installed in the field panel.

The speed sensor signal input unit of the digital controller 300 is configured to be selectable through MPU (Magnetic Pickup Unit) or PPU (Proximity Probe Unit) jumper settings, and each channel is isolated from each other. The MPU can have a 1 to 25 VRMS input voltage range, and the PPU can have a 16 to 28 VDC input voltage range. The auxiliary feed water pump control facility can receive two MPU sensor signals from the field.

The digital controller 300 may control the flow rate of steam flowing into the auxiliary feed water pump turbine through the actuator through the signal conversion in EGR according to the speed control set value input from the user and the speed signal calculated by the speed PID control. have.

에서 최대 0.25%의 정확도를 가질 수 있다. 디지털 제어기(300)에 입력된 속도제어 설정 값과 PID 제어에 의하여 연산된 속도신호는 EGR에서 Signal Converter를 거쳐 -300 ~ 300mA의 신호로 출력되어, 보조급수펌프터빈에 유입되는 스팀의 유량을 제어할 수 있다.The actuator driver output unit of the digital controller 300 may have a resolution of 10 bits, and may select and output 4 to 20 mA or 20 to 160 mA according to the field actuator in software, 25

can have an accuracy of up to 0.25% in The speed control set value input to the digital controller 300 and the speed signal calculated by the PID control are output as a signal of -300 ~ 300mA from the EGR through the Signal Converter to control the flow rate of steam flowing into the auxiliary feed water pump turbine. can do.

A detailed operation of the digital controller 300 according to the present invention will be described as an example. The turbine speed of the nuclear power plant auxiliary feedwater pump can be sensed by two MPUs.

The higher of the two speed signals that detect the speed of the turbine (High Select Signal, HSS) can be used for final control and electrical or mechanical overspeed protection. The speed target value can be basically set through the increase/decrease operation switch.

The range of the speed target value may be set between a minimum value and a maximum value of the governor speed target. The speed target value can also be changed in the MCR through the analog input. However, it can be used only when the contact input signal for allowing speed setting in the MCR is input and the set value is greater than or equal to the governor speed minimum value. The range of the speed target value in the MCR can be set according to the speed range programmed in the 4-20mA signal.

The MPU gear ratio and MPU tooth number can be entered into the internal program from the operator to calculate the actual turbine speed. The speed PID may compare the sensed speed signal with a speed target value and send a signal to the governor valve actuator 100 . The speed PID can be used by selecting one of several modes according to the configuration, and the speed PID can be used through the speed control mode. In the speed control mode, PID can control only the turbine speed or frequency, ignoring the supplied load.

A Human Machine Interface (HMI) program that could not be implemented in the existing analog control method may be implemented in the operation support device 400 connected to the digital controller 300 through wired/wireless communication. The driving support device 400 may be provided with a touch function in consideration of the operator's ease of use in the field, and may set security such as access restriction according to authority. The HMI program allows you to check the start and control of the pump, input/output data, parameters, and alarms in real time. can be analyzed in detail. This enabled flexible failure prediction analysis that could not be applied in the existing auxiliary water supply control system, greatly increasing the overall availability and reliability of the system.

7 is a flowchart illustrating a method for controlling a nuclear power plant auxiliary feed water pump turbine according to another embodiment of the present invention.

In the method for controlling the auxiliary feed water pump turbine of a nuclear power plant according to another embodiment of the present invention, first, the turbine speed sensor unit 200 measures the speed of the auxiliary feed water pump turbine using the sensor ( S100 ). Then, the digital controller 300 including the central processing unit and control software receives a predetermined parameter from the user and receives the speed of the auxiliary feed water pump turbine from the turbine speed sensor unit 200 to drive the governor valve 100 . to control (S200). Then, the governor valve driving device 100 adjusts the operating speed of the auxiliary feed water pump turbine according to the control of the digital controller 300 (S300).

In addition, the operation support device 400 connected to the digital controller 300 through wired/wireless communication may display the status of the auxiliary feed water pump turbine from a distance from the digital controller 300 and input a predetermined parameter (S400). ).

On the other hand, step S200 is to control the flow rate of steam flowing into the auxiliary feed water pump turbine through the actuator through signal conversion in EGR according to the speed control set value input from the user and the speed signal calculated by the speed PID control. have.

Meanwhile, in step S200, the governor valve is driven by checking the measured value and the target value of the control target according to the control method desired by the user, and adjusting the response and slope of the control target through the deviation of the measured value and the target value and the PID control. It may be to control the device to perform the auxiliary feed water pump turbine speed control and load control.

The system described above may be implemented as a hardware component, a software component, and/or a combination of the hardware component and the software component. For example, devices and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA). , a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions, may be implemented using one or more general purpose or special purpose computers. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For convenience of understanding, although one processing device is sometimes described as being used, one of ordinary skill in the art will recognize that the processing device includes a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that can include For example, the processing device may include a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as parallel processors.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and carry out program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Although described and illustrated in relation to a preferred embodiment for illustrating the technical idea of the present invention above, the present invention is not limited to the configuration and operation as shown and described as such, and deviates from the scope of the technical idea. It will be appreciated that many changes and modifications may be made to the present invention without reference to the invention. Accordingly, all such suitable alterations and modifications and equivalents are to be considered as falling within the scope of the present invention.

100 governor valve actuator
200 turbine speed sensor
300 digital controller
400 Driving support device

Claims (8)

In the nuclear power plant auxiliary feed water pump turbine control system,
a governor valve driving device for regulating the operating speed of the auxiliary feed water pump turbine;
a turbine speed sensor unit for measuring the speed of the auxiliary feed water pump turbine using a sensor; and
A digital controller that receives a predetermined parameter from a user in a digital control method including a central processing unit and control software, receives the speed of the auxiliary feed water pump turbine from the turbine speed sensor unit, and controls the governor valve driving device; includes,
The digital controller controls the flow rate of steam flowing into the auxiliary feed water pump turbine through an actuator through signal conversion from EGR according to a speed control set value input from a user and a speed signal calculated by speed PID control A nuclear power plant auxiliary feed water pump turbine control system.
According to claim 1,
Nuclear power plant auxiliary, characterized in that it further comprises a; operation support device connected to the digital controller through wired/wireless communication to display the status of the auxiliary feed water pump turbine from a distance from the digital controller and input the predetermined parameters. Feedwater Pump Turbine Control System.
delete According to claim 1,
The digital controller checks the measured value and target value of the control target according to the control method desired by the user, and controls the measurement value and target value for Speed, EXTR, Auxiliary, and Cascade values and PID control for the control target. The auxiliary feed water pump turbine control system of a nuclear power plant, characterized in that the auxiliary feed water pump turbine speed control and load control are performed by controlling the governor valve driving device by adjusting the response and slope.
In the control method of the auxiliary feed water pump turbine of a nuclear power plant,
Measuring the speed of the auxiliary feed water pump turbine using a turbine speed sensor unit;
controlling a governor valve driving device by receiving, by a digital controller including a central processing unit and control software, a predetermined parameter from a user and receiving a speed of the auxiliary feed water pump turbine from the turbine speed sensor unit; and
adjusting, by the governor valve driving device, the operating speed of the auxiliary feed water pump turbine according to the control of the digital controller;
In the step of the digital controller controlling the governor valve driving device, the signal is converted from EGR according to the speed control set value input from the user and the speed signal calculated by the speed PID control, and then introduced into the auxiliary feed water pump turbine through the actuator. A nuclear power plant auxiliary feed water pump turbine control method, characterized in that controlling the flow rate of steam.
6. The method of claim 5,
and allowing the operation support device connected to the digital controller through wired/wireless communication to display the status of the auxiliary feedwater pump turbine from a distance from the digital controller and input the predetermined parameters. A method of controlling a power plant auxiliary feedwater pump turbine.
delete 6. The method of claim 5,
The step of the digital controller controlling the governor valve driving device includes checking the measured values and target values for the Speed, EXTR, Auxiliary, and Cascade values of the control target according to the control method desired by the user, and A nuclear power plant auxiliary feed water pump turbine control method, characterized in that the auxiliary feed water pump turbine speed control and load control are performed by controlling the governor valve driving device by adjusting a response and slope to a control target through deviation and PID control.

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