基于FPGA的反应堆保护系统可靠性建模与分析

Reliability Modeling and Analysis of Reactor Protection System Based on FPGA

为建立基于现场可编程门阵列(FPGA)的反应堆保护系统的可靠性模型,以对系统安全提供有效的分析与验证手段。本研究采用故障树、随机Petri网模型,对CANDU堆1号停堆系统(SDS1)单通道进行可靠性建模与分析。对故障树模型分析得到最小割集,以顶事件发生概率作为系统故障概率,在考虑故障检测、维修与定期试验情况下对随机Petri网模型进行仿真得到系统的拒动概率。研究结果表明,故障树和状态空间方法存在一定局限性,随机Petri网能够反映故障检测与定期试验对反应堆保护系统的影响,可以动态地反映系统可靠性,并且避免了状态空间爆炸问题。因此,本研究建立的随机Petri网模型适用于反应堆保护系统的可靠性建模。

In order to establish a reactor protection system reliability model based on the field programmable gate array(FPGA)to provide effective analysis and verification methods for system safety,this study adopts the fault tree and stochastic Petri net(SPN)models to perform reliability modeling and analysis for the single channel of CANDU reactor shutdown system 1(SDS1).The analysis by fault tree model provides the minimal cut set.With the top event probability taken as the system fault probability,and in consideration of the fault detection,maintenance and periodic testing,the probability of rejection of the system is obtained by the stochastic Petri net model simulation.The results show that both the fault tree and state space representation are limited to a certain extent,while the stochastic Petri net can reflect the impact of fault detection and periodic tests on the reactor protection system,dynamically present the system reliability,and avoid the problem of state space explosion.Therefore,the stochastic Petri net model established in this study is suitable for the reliability modeling of the reactor protection system.