Locking control priority selection module for instrument control system of nuclear power plant

Abstract

The invention discloses a locking control priority selection module for an instrument control system of a nuclear power plant. An input channel transmits an external signal to two CPLDs at the same time, and the two CPLDs complete the priority logic operation of the external signal according to the priority logic, and then output a priority result; the two CPLDs interact with each other to obtain a priority result; the CPLD obtains the priority result of the CPLD at the opposite side and then compares the priority result with the priority result of the CPLD; when the comparison priority result of any CPLD is inconsistent, the CPLD is started, locking instructions are outputted to respective corresponding network interfaces; the network interface obtain the fault output value from the outside and send the fault output values and the locking instructions to an output lock together; when the output lock obtains the locking instructions and the fault output values at the same time, the output lock is in a locking state, the priority result of the CPLD is locked not to be output, and the fault output value is outputted to the output channel.

Description

technical field [0001] The invention relates to the technical field of nuclear power, in particular to a blocking control optimization module used in an instrument and control system of a nuclear power plant. Background technique [0002] The optimization module is an important part of the safety level instrument and control platform of the nuclear power plant, which is mainly used to drive the pumps, valves and other equipment of the special safety facilities and related support systems. The driving signal of the driving device can be given by multiple systems. In order to prevent the conflict between the signals from causing the abnormal operation of the driven device, the optimization module needs to judge the priority of the signal to ensure that the driven device performs the action according to the correct signal. The optimal module not only provides the control interface for the driven equipment, but also needs to prioritize the automatic commands and manual commands ...

AI Technical Summary

Problems solved by technology

[0003] In the existing optimization module technology field, for safety and reliability, it is generally preferred to use hard logic gates to build priority logic, which can be realized simply, efficiently and safely when the number of input channels is low, but when the number of input channels For a long time, if you continue to use hard logic gates to build, it will lead to complicated circuits, which will affect the safety performance. Therefore, at this time, CPLD is generally used to implement priority logic by programming methods.

In the existing technology that uses CPLD to implement priority logic, in order to ensure that the CPLD itself is in a normal working state, the method is to use regular detection means, that is, switch it to the test mode within a certain period of time, and then input the test signal externally. If the CPLD can output the correct expected priority result, it is considered that the priority logic function of the CPLD is normal. If it cannot output the correct expected priority result, it is considered that the priority logic function of the CPLD is abnormal and needs to be overhauled. Difficult to overcome. Since the detection method is initiated periodically, when the CPLD priority logic fault occurs before the detection method is initiated, it cannot be detected in time, which will cause the wrong priority result to be output, that is, when the priority module fails, the preferred module The output of the device may be out of control, causing unexpected actions of the driven equipment and causing safety accidents

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