基于威布尔分布的动态故障树对DEH控制系统优化的评价研究

对于火电厂汽轮机组并网运行阶段的数字电液控制系统(Digital Electro-Hydraulic Control System，DEH)的不足，进行了逻辑优化。进而需要对优化后DEH控制系统的可靠性进行评价。目前可靠性评价中，大都假设设备运行于偶然失效期，失效率假定为常数。然而，实践证明当设备运行于耗损失效期时，失效率服从威布尔分布。因此，将威布尔分布和马尔可夫模型相结合，建立了优化后DEH控制系统失效的动态故障树(Dynamic Fault Tree，DFT) 模型。对运行于耗损失效期的DEH控制系统的可靠性进行了研究，验证了优化后DEH控制系统可靠性的提高，为设备长时间运行后的可靠性评估提供依据。

Research of assessment for the optimized DEH control system with DFT based on Weibull distribution

The dynamic fault tree (DFT) model is constructed based on the optimized DEH control system which is connecting the grid .Different from the former research about the reliability in which the failure rate is assumed constant when the devices are running in the Normal Life Period, now when the devices are running in the Wear-out Period the failure rate changes along with the time goes ,it obeys Weibull distribution. Therefore, making a research about the reliability assessment by using Weibull distribution combined with Markov chain when the DEH control system in the Wear-out Period , confirmed that the reliability rise after the devices were optimized , providing the basis for the devices reliability evaluation in the future .