EFFECT ANALYSIS OF POWER SUPPLY TOPOLOGY ON THE RELIABILITY OF THE REACTOR PROTECTION SYSTEM

As a clean energy source, Low Temperature Reactor can be used for heating, desalination, industrial steam production, summer cooling, etc. It still has good application prospects at present. The reactor protection system is one of the important safety systems in Low Temperature Reactor, thus improving the reliability of the protection system can enhance the safety level and economic benefits of the reactors. The reliability of the protection system is directly related to its system structure, the quality of its components, and the power supply topology. The effect of the third factor is analyzed in this article. In the aspect of system reliability analysis, the RBD method is widely used and has many public research results. Based on the block diagram of protection system, this article establishes the RBD that considers the operation failure. According to the foregoing RBD, the protection system reliability is calculated, the minimum cut sets that can cause the protection system failure are analyzed, the different importance measures of each device in the protection system is determined, and the occurrence probability of the minimum cut sets and the importance measures are sorted as a basis for subsequent optimization of power supply topology. The Low Temperature Reactor protection system in this article is mainly composed of transducer, set-point comparison unit, logic coincidence unit, and safety trigger unit. The power supply of these units have many possible topological structures, which have different complexity and different reliability levels. Three improvement approaches are proposed for the power supply topological structure of transducer, set-point comparison unit and logic coincidence unit, the reliability of the optimized protection system is calculated and analyzed. The results show that by improving the power supply topology, the reliability of the protection system is improved without increasing the components' quality and redundancy.