铁道供电系统信息流延时的拉丁超立方抽样蒙特卡洛模拟  

Latin Hypercube Sampling Monte Carlo Simulation for the Information Flow Time-Delay of Railway Power Supply System

作　　者：屈志坚[1] 刘明光[2] 刘靖[3] 曹洪睿[4] 杨罡[2] 刘铁[2] 

机构地区：[1]华东交通大学电气工程学院,江西南昌330013 [2]北京交通大学电气工程学院,北京100044 [3]中国原子能科学研究院国家能源快堆工程研发实验中心,北京102413 [4]西南交通大学电气工程学院,四川成都611756

出　　处：《中国铁道科学》2012年第5期82-90,共9页China Railway Science

基　　金：国家自然科学基金资助项目(51267005);江西省教育厅青年科学基金资助项目(GJJ10138;GJJ11116)

摘　　要：针对铁道供电系统信息流处理中的延时问题,建立主备模式的通信预处理队列模型、并列服务器实时队列模型和服务器轮询队列模型。利用拉丁超立方抽样技术和蒙特卡洛方法对信息流服务过程进行研究,运用统计学方法得出排队参数概率分布、置信区间和模拟次数之间的关系。以2M光纤通信为例,取平均到达率1 024kB·s-1和平均服务率1 500kB·s-1进行蒙特卡洛模拟。结果表明:报文字节处理服务延时可控制在2～3ms左右;验证了用拉丁超立方抽样代替随机抽样,可减少蒙特卡洛模拟的次数。比较并列服务器和单服务器的实时处理队列平均等待时间模拟结果可知:相同条件下单服务器的实时处理队列平均等待时间超出10ms的概率为82.95%,超出13ms的概率为56.08%,均大于并列服务器实时处理队列平均等待时间的概率。因此,采用并列服务器配置方式可减少铁道供电系统信息流实时处理中的平均等待延时。Primary-backup communication preprocessing queue model, parallel server real-time queue model and server polling queue model are put forward for solving time-delay problem of information flow processing in railway power supply system. Latin hypercube sampling and Monte Carlo simulation are used to study the service process of information flow, and the relationships among the probability distribution of queuing parameters, confidence interval and simulation times are obtained by means of statistical method. Taking 2 M optical fiber communication for example, 1024 and 1 500kB&middots-1 is respectively adopted for the average arrival rate and average service rate to carry through Monte Carlo simulation. Results show that the time-delay for packet byte processing service can be controlled at about 2~3 ms, and it is verified that using Latin hypercube sampling instead of random sampling can reduce the number of Monte Carlo simulation. The simulation results of the average waiting time for real-time processing queue of parallel server and single server are compared. It is clear that, under the same conditions, the probability is 82.95% for single server when the average waiting time of real-time processing queue exceeds 10 ms, and the probability is 56.08% when the average waiting time exceeds 13 ms, both are greater than that of parallel server. Accordingly, parallel server configuration mode can reduce the average waiting time delay of information flow processing in real-time in railway power supply system.

关 键 词：电气化铁道 供电系统 信息流 延时 拉丁超立方抽样 蒙特卡洛模拟 概率分布 

分 类 号：U224.911[交通运输工程—道路与铁道工程]