大众捷运不断电系统可用度及可靠度分析

Availability and Reliability Analysis of Uninterrupted Power Supply System Adopted in Mass Rapid Transit

分析单一组件的历时可用度行为,探讨对数常态分布可靠度(中位数tmed以及误差因子EF)和指数分布维修度(平均维修时间MTTR)对其可用度的影响,得出数值分析结果:在固定稳态可用度ASS以及平均维修时间MTTR的情况下,中位数tmed越小(或是误差因子EF越大)的组件历时可用度越早单调下降且下降量越大,越晚回弹至其稳态可用度;在固定稳态可用度ASS以及误差因子EF的情况下,具有越大平均维修时间MTTR的组件历时可用度越晚单调下降但下降量不变,也越晚回弹至其稳态可用度。建立不断电系统可用度以及可靠度的分析模式,探讨正常供电、电池备援以及旁通供电3种不同模式对整体可用度以及可靠度的贡献程度,得出数值分析结果:正常供电模式贡献了绝大部分的整体不断电可用度;不考虑维修作业能力,整体不断电系统的可靠度参数MTTF为1184301h。

The purposes of this paper are twofold;one is to analyze the time variant availability behavior of a single component in order to estimate the impact of lognormal reliability distribution（median time to failure,tmed,and Error Factor,EF）and exponential maintainability distribution（mean time to repair,MTTR）on its availability.The numerical results show：· The smaller the tmed（or the larger the EF）,the earlier the mono-decrease of component availability,the larger the fall and the later the bounce to its steady state availability under the fixed steady state availability and MTTR.· The larger the MTTR,the later the mono-decrease of component availability while the fall being constant,and the later the bounce to its steady state availability under the fixed steady state availability and EF.The other purpose of this paper is to establish a calculation model of system availability and reliability to evaluate the impact of different modes（normal power,battery backup and bypass route）of power supply on system availability and reliability.The numerical result shows：· The system availability of UPS is mainly supported by normal power supply mode.· System-wide UPS reliability parameter MTTF is 1,184,301h without consideration of maintenance capability.