CN-122018416-A - Rod position control system based on single set of PLC and control method thereof

CN122018416ACN 122018416 ACN122018416 ACN 122018416ACN-122018416-A

Abstract

The invention discloses a rod control system and a control method of a single PLC, relates to the field of rod position control of nuclear power plants, and aims to solve the problems of large occupied space and high manufacturing cost of the existing PLC rod control system. The system comprises a human-computer interface, a PLC control unit and a rod position control machine box, wherein the human-computer interface can transmit control signals to the PLC control unit and can also receive feedback signals of the PLC control unit and display the feedback signals, the PLC control unit comprises a digital quantity input module, a digital quantity output module, a PLC module and a communication module, a hardware part of the PLC control unit adopts a multi-slot machine frame, and the rod control machine box comprises a lifting machine box, a transmitting machine box and a holding machine box, and lifting, transmitting and holding actions are performed after signals of the PLC control unit are received.

Inventors

CHEN SHANAN
ZHANG WEIWEI
TAN DECHAO
CHEN YONG
MENG HAO
ZHU ZHAOYUAN
XIA HAO
YANG ZHOU
TANG XINGDONG
ZHENG JINFU
XIN HONGWEI
Shao Qiankun

Assignees

海南核电有限公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (10)

1. A rod position control system based on a single set of PLC is characterized by comprising a human-computer interface, a PLC control unit and a rod position control machine box, wherein the human-computer interface can transmit control signals to the PLC control unit and can also receive feedback signals of the PLC control unit for display, the PLC control unit comprises a digital quantity input module, a digital quantity output module, a PLC module and a communication module, a hardware part of the PLC control unit adopts a multi-slot machine frame, and the rod control machine box comprises a lifting machine box, a transmission machine box and a holding machine box, and lifting, transmitting and holding actions are performed after signals of the PLC control unit are received.
2. The rod position control system based on the single set of PLC according to claim 1, wherein the feedback signals of the PLC control unit received by the human-computer interface comprise equipment fault conditions and running step number conditions.
3. The bar position control system based on the single-set PLC of claim 1, wherein in the multi-slot rack, a power module, a PLC module, a communication module and a digital quantity output module respectively occupy 1 slot position, and a digital quantity input module occupies 2 slots positions and is reserved with a standby slot position.
4. The rod position control system based on the single-set PLC according to claim 1, wherein the PLC module can excite and generate large and small current output signals of the lifting coil, the transmitting coil and the holding coil through logic judgment output signals, and the signals are transmitted to the lifting case, the transmitting case and the holding case through the digital quantity output module.
5. The single set of PLC based rod position control system of claim 4, wherein when the PLC rod position control system fails in an emergency, the lift coil and the transfer coil are energized simultaneously so that simultaneous actuation of the lift and transfer housings ensures that the control rod does not fall out due to the failure.
6. The rod position control method based on the single set of PLC is characterized by comprising 7 steps, wherein rod position control is performed according to the sequence from the first step to the seventh step, the first step is analog signal processing, and rod speed is converted into a period for rod speed control through signal conversion; the method comprises the steps of receiving and executing an instruction, receiving an external lifting instruction and an external inserting instruction, interlocking the lifting instruction and the external inserting instruction, enabling lifting and inserting not to be carried out simultaneously, initializing a PLC logic variable, initializing a variable in a PLC module when the PLC is powered on or reset for the first time, resetting the PLC, clearing a counter, resetting a holding, transmitting and lifting case, judging whether the equipment has an emergency fault in a fault mode, judging whether the equipment has the emergency fault or not in the step, starting to judge if the lifting instruction can be output in the step, jumping to the step I if the lifting instruction can be output in the step I, and not carrying out the step seven, judging if the inserting instruction can be formed in the step I, carrying out the step II, returning to the step I for periodic circulation if the inserting instruction can be formed in the step I, designing for reducing the PLC logic operation time in the step I, outputting a lifting instruction and a signal of adding 1 in the accumulated step I for periodic circulation, and carrying out the step I for periodic circulation if the inserting instruction and the signal of adding 1 in the accumulated step I for periodic circulation.
7. The method of claim 6, wherein the step three PLC logic variable initialization variables include a start time and an end time for lifting, transmitting and maintaining three coil currents, an internal count, a start flag and an end flag for the coil currents, and a lock-up bit for lifting and inserting.
8. The method according to claim 6, wherein the step seven and the step two are not executed if the condition for forming the lifting command is satisfied, the step one is directly executed, and then the step one is returned to continue to execute the logic operation in this order, in which case the PLC executes the steps one, two, three, four, five, six, and one.
9. The method according to claim 6, wherein when the PLC executes the step six, if the condition for forming the lifting command is not satisfied, the step seven is executed, the judgment is performed again, if the condition for forming the inserting command is satisfied, the step two is executed, and then the step one is returned to continue to execute the logic operation, in which case the PLC executes the steps one, two, three, four, five, six, seven, two, and one.
10. The method according to claim 6, wherein when the PLC performs the judgment from the step seven, if the condition for forming the insert instruction is not satisfied, the logic operation is re-performed in the step one, and the PLC performs the steps one, two, three, four, five, six, seven, and one in this case.

Description

Rod position control system based on single set of PLC and control method thereof Technical Field The invention belongs to the field of rod position control of nuclear power plants, and particularly relates to a rod position control system based on a single set of PLC and a control method thereof. Background The reactor is a core device of a nuclear power station, a control and position monitoring system of a reactor control rod, hereinafter referred to as a rod control system for short, is a key instrument and control system for controlling the power of the reactor, and a control logic part of the rod control system of a certain nuclear power station mainly comprises a PLC. From the present, the nuclear power station rod control system consists of 3 sets of PLCs, namely a logic cabinet PLC, a power cabinet PLC and a processing cabinet PLC. The logic cabinet PLC receives signals of rod group selection, lifting, inserting, mode selection, operation commands and the like from a main control room, an upper computer picture and other systems. And through logic judgment, the logic cabinet periodically generates lifting and inserting commands and finally sends the lifting and inserting commands to the power cabinet. The power cabinet PLC receives the lifting and inserting commands of the logic cabinet, generates time sequence excitation of three coils, and outputs the time sequence excitation to the lifting machine box, the transmission machine box and the holding machine box. The processing cabinet PLC receives the rod position measuring signal of the measuring cabinet, calculates, judges the generated alarm signal and transmits the signal to the alarm system. In other established nuclear power plants in China, the rod control system is designed by adopting the same structure, and if the rod control clamping piece testing cabinet is designed by adopting the structure, the rod control clamping piece testing cabinet can be high in manufacturing cost and large in occupied space. Disclosure of Invention The invention aims to provide a rod position control system based on a single set of PLC and a control method thereof, which solve the problem that the existing rod control system of a nuclear power station needs three sets of PLCs, and reduce the system cost while reducing the occupied space of the rod control system. The rod position control system based on the single-set PLC comprises a human-computer interface, a PLC control unit and a rod position control machine box, wherein the human-computer interface can transmit control signals to the PLC control unit and can also receive feedback signals of the PLC control unit and display the feedback signals, the PLC control unit comprises a digital quantity input module, a digital quantity output module, a PLC module and a communication module, a hardware part of the PLC control unit adopts a multi-slot machine frame, the rod control machine box comprises a lifting machine box, a transmission machine box and a holding machine box, and lifting, transmitting and holding actions are performed after signals of the PLC control unit are received. The rod position control system based on the single set of PLC comprises the equipment fault condition and the running step number condition, wherein the feedback signals of the PLC control unit received by the human-computer interface. In the rod position control system based on the single set of PLC, a power module, a PLC module, a communication module and a digital quantity output module respectively occupy 1 slot position in the multi-slot frame, and a digital quantity input module occupies 2 slots and is reserved with a standby slot position. According to the rod position control system based on the single set of PLC, the PLC module can excite and generate large and small current output signals of the lifting coil, the transmitting coil and the holding coil through logic judgment of the output signals, and the signals are transmitted to the lifting case, the transmitting case and the holding case through the digital quantity output module. According to the rod position control system based on the single PLC, when the PLC rod position control system has an emergency fault, the lifting coil and the transfer coil are electrified simultaneously, so that the lifting case and the transfer case act simultaneously to ensure that the control rod cannot fall down due to the fault. The rod position control method based on the single PLC comprises 7 steps, wherein rod position control is carried out according to the sequence from the first step to the seventh step, the first step is analog signal processing, and rod speed is converted into a period for rod speed control through signal conversion; the method comprises the steps of receiving and executing an instruction, receiving an external lifting instruction and an external inserting instruction, interlocking the lifting instruction and the external inserting instruction, enabling lifting