计轴系统特殊故障的分析与解决方案

张宏强(无锡地铁集团有限公司建设分公司,214023,无锡∥工程师)



计轴系统特殊故障的分析与解决方案

张宏强
(无锡地铁集团有限公司建设分公司,214023,无锡∥工程师)

摘 要计轴系统是一种重要的轨道交通信号设备,广泛应用于铁路、城市轨道交通领域。以无锡地铁2号线计轴系统故障为例,分析了在2号线运营环境下的电磁干扰对计轴轨旁设备产生“脉冲不计数”故障(WPOZ)的原因,提出了设置检测点至“高功率”模式的解决方案。测试结果表明,所推荐的检测点设置方法可大幅度降低受扰机率。

关键词地铁;计轴系统;故障;电磁干扰

Author′s address Wuxi Metro Group Co.,Ltd.,214023, Wuxi,China

无锡地铁2号线计轴系统在调试期间出现了相关区段受扰故障频发的问题。本文讨论该故障的成因并录求解决方案。

1　计轴系统

1.1计轴系统功能

计轴设备是通过安装在所监测轨道区段两端的计轴轨道传感器,对驶入与驶出该区段的列车轴数进行计算,从而完成对该区段空闲与占用状态的判断。当列车完整出清区段后,区段表示为空闲,否则表示为占用。作为区段状态检查的信号设备,计轴设备的作用和轨道电路等效。

1.2AzLM计轴系统的构成

Az LM计轴系统包括室内设备和室外设备两部分。室内设备主要为安装在封闭机柜中的计轴评估器(ACE),室外设备为计轴检测点。图1位Az LM计轴系统构成示意图。

图1　Az LM计轴系统构成示意图

1.3Az LM计轴系统工作原理

图2为Az LM计轴系统解决方案示意图。

图2　Az LM计轴系统解决方案示意图

(1)轨道磁头(车轮传感器):由两个安装在同一根钢轨上的物理偏移线圈装置Sk1和Sk2组成。轨道外侧是两个Tx线圈,轨道内侧为两个Rx线圈,产生约为30 k Hz的不同频率的两种信号,在轨道附近形成电磁场。这些装置提供了两个时间偏移的感应电压,利用这些装置就可以在电子单元中确定轮轴是否通过以及轮轴的行驶方向,因为基于可靠性原因,磁头中除线圈外不存在其他电子部件。

(2)车轮电子检测盒(EAK):电子单元E-ES 30 H为Tx发送磁头供电,检测并计算轮轴脉冲,监控磁头,进行自检并向室内主机ACE发送包含计数和监控信息的报文。计数、监控和报文生成功能由两个受计轴主机安全模块监控的独立微控器执行。

(3)室内计轴评估单元:通过评估室外计轴区段计入及计出的轴数来判断区段是否空闲。

2　计轴系统故障分析

无锡地铁2号线全线采用了Az LM计轴系统,自列车上线调试以来计轴单点受扰故障频发,统计数据显示计轴故障累计发生30余次,涵盖全线多个集中区。

通过定期搜集计轴的诊断文件,以预估潜在的问题,并对全线计轴安装、关联设备及数据参数进行现场检查和分析,初步得出以下结论:故障发生在列车进站或道岔前;计轴本身质量、安装及软件配置没有问题;故障与附近接地、杂散电流环境无关;与联锁系统接口无关;受影响的计轴部件位于室外磁头与轨旁安装盒之间,与室内设备无关。

通过调研国内主要地铁城市计轴系统运行与故障情况,未发现类似故障,该故障类型属国内首例新的计轴故障。

为找出故障的根本原因,使用示波器进行现场测量,以扑捉故障波形。检测设备(带有记录功能的示波器)安装在映月湖公园站的检测点AC204J处(站台入口检测点)。与该检测点相对应的ACE安装在查桥站。所有的检测点采用双线标准ISDN(综合业务数字网)连接至远程电源。示波器设置方式为:对预定义阈值范围内的所有模拟信号进行记录,评估板的数字器做平行评估记录,以与诊断信息中的事件同步。

此次测试历时超过60 h,共记录经过列车300余列。图3显示其中有60多列列车产生电磁干扰信号,5列列车使区段受扰。

在对检测结果进行评估后发现,EMI干扰的唯一来源是车辆。列车的第一节和最后一节车厢从未发生过干扰。有时只有一节车厢(主要是第二节车厢),但也有两节或三节车厢发生干扰的情况。没有发现其他特殊案例。由此可以假定,产生EMI干扰的车厢号取决于列车运营方式和系统特定条件。图4是车厢数量与干扰数量的记录。因为有些情况下是一节以上的车厢产生EMI干扰,干扰现象的总数与产生干扰的车厢数量并不一致。

图3　检测列车数量

图4　产生EMI干扰现象的车厢数量

作为区段干扰的主要原因,识别出一种故障现象,系统定义为WPOZ(脉冲不计数)。每当电子单元的评估板检测到一个不能被识别为正确车轮脉冲的电磁脉冲时,就会产生此诊断信息。当一个检测点两个磁头中的任意一个受影响时就会出现这种情况。因为这种情形无法与磁头失效进行区分,基于安全考虑将检测点设置为受扰状态。产生这种错误的车轮脉冲的条件为:至少一个磁头在磁头工作频率范围(约30 k Hz)内受电磁干扰影响;脉冲的幅值达到足够高值,足以产生数字脉冲,且数字脉冲长于4 ms。

根据统计分析,选择在WPOZ出现次数最多的检测点进行测量(在映月湖公园站进站口检测点AC204J)。分析进一步表明:不是2号线所有检测点都受到相同强度的影响,故障现象(报出WPOZ)主要集中在进站口或在岔道前区域内,区间的检测点则不受影响;干扰与列车的运行有关。图5为一列有电磁干扰列车的采集波形。

3　计轴系统故障解决措施

为了避免该不明干扰,决定通过增加磁头的信噪比提高抗干扰能力。计轴《ZP30H安装调试手册(V2.0)》中4.4描述“这个特性对于3CR01836AEAA或更新的模拟板可用。在特殊应用中,发送磁头的供电可以通过将模拟板上的开关S3打在位置2来提高。这样会产生更好的信噪比,但是会降低轨旁电缆的最大允许阻抗。”

图5　一列有电磁干扰列车的采集波形(原检测点设置)

图6　一列有电磁干扰但没有引起WPOZ列车的采集波形(调整参数设置后的检测点)

通过设置检测点至“高功率”模式(出厂默认值是“正常功率”),车轮通过所产生的脉冲幅值可提高25%。这允许对磁头进行调整以进一步增加信噪比。“高功率”的设置是另一种出厂默认设置的选项,是系统允许的一种设置。

通过示波器检测试验,并对测量设备加以调整,通过对调整后检测数据的统计分析,以及对日志文件的分析进行辨别,未发现有干扰达到检测点的触发值,从而导致无效轮脉冲的产生。测试显示该调整措施是成功有效的。图6为调整参数设置后,一列有电磁干扰但没有引起WPOZ列车的采集波形。

4　结语

通过现场测量捕捉到了一种新的计轴系统故障的源头,该故障都发生在列车运行过程中并存在于列车车厢中部。通过设置检测点至“高功率”模式,提高信噪比,干扰的概率大幅减小,彻底避免来自于车厢中部的不明干扰。

参考文献

[1] 北京泰雷兹交通自动化控制系统有限公司.Az LM工程手册(3CR01800xxxx GAAFQ)[G].北京:北京泰雷兹交通自动化控制系统有限公司,2014.

[2] 北京泰雷兹交通自动化控制系统有限公司.ZP 30 H安装指南(3CR01820Axxx583QQ)[G].北京:北京泰雷兹交通自动化控制系统有限公司,2014.

[3] 北京泰雷兹交通自动化控制系统有限公司.Az LM型计轴系统产品说明书(V3.0)[G].北京:北京泰雷兹交通自动化控制系统有限公司,2014.

[4] 高玉,王洪波.基于状态机的计轴处理模型研究[J].城市轨道交通研究,2014(8):112.

(Continued from Special Commentary)

comparatively cheaper.Therefore,few American people would choose both slow and uneconomic railways to travel. According to statistics,in the United States of America,in the passenger carriage of beyond 80 km,the proportions undertaken by various transport modes are as follows:cars accounted for 56%;air,41%;buses,2%;railways,only 1%. Such a passenger transport structure almost makes railways become something dispensable,that is to say,as well without it as with it.However,such a passenger transport structure could not be promoted.The American population only accounts for 5% of the world′s population,but they consume 25% of the world's energy sources.If the whole world copies the above American mode,it would need 5 earths to maintain the balance between supply and demand.Even more worryingly,the carbon-emissions pollution caused by automobile exhaust has the accumulation effects.Due to Germany's Volkswagen′s resorting to deceit in testing of car exhaust emissions,the United States of America imposed heavy penalties on this car company.This is a must.But,more importantly,facing the increasingly serious pollution caused by car exhaust emissions, the United States should change its irrational structure of passenger transportation.

Secondly,the America's economic structure,natural conditions and population distributions make its high-speed railwayplan have difficulty in taking a step.In the United States,1/7 industries are automobile-related,1/6 employment population are automobile-related.To develop high-speed railways will be opposed by these enterprises and their employees.Judging from the geographical factors of the United States of America,except the several densely-populated city belts of the east and west coasts,most of its areas are sparsely populated.Thus,the passenger transportation demand for high-speed rail is not very urgent.

Thirdly,all the states of the USA have a high degree of autonomy,which makes the federal government's plans for high-speed rail difficult to achieve.Take the 135 km high-speed rail project of Florida State′s connecting with Orlando and Tampa that had included in the Federal Government′s plan as an example.The Federal Government expressed its willingness to undertake the 90% construction costs,and therefore gave Florida State the $2.4 billion federal funding.But after calculating the economic accounts,the state government returned exactly the number of funding because they thought that there were the possibilities of a potential over-expenditure and losses after operation in this high-speed rail project.

Fourthly,the American electoral politics led to the situation that the Republican Party opposed that the Democratic Party agreed(In fact,not only for high-speed rail,but also for gun control as well.).The Republican Party members of all the state parliaments opposed Obama's high-speed rail plan.This time,it was not easy that the high-speed railway of the American western express line,which was a Sino-American cooperative project,could break the tight encirclement and set its own banner.The reason for this is as follows.The former California Governor Arnold Schwarzenegger,a famous film actor,who has many fans in China,embraced the visit to China.Although Arnold Schwarzenegger is a Republican,he rode the high-speed rail trains in China,which were convenient and comfortable,and which left him a good impression,so that he no longer opposed the high-speed railway construction.Thereafter,Mr.Brown who took over as governor is a democrat. Then,the America's first high-speed rail would naturally make a breakthrough in California.The total investment of the 370 km-full-length high-speed railway project of Western Express Line connecting Los Angeles with Las Vegas is about$12.7 billion.Currently,the two sides of China and the United States have carried out the related work,including identifying financing plan.The project is expected to start construction at the end of September,2016.

Although the high-speed rail constructions in the United States encountered above-mentioned all sorts of problems,we are still full of expectations for American high-speed rail constructions.This also has the following four reasons.

Firstly,the United States used to have 412 000 km railways.Up to this day,although 130 000 km railways have been dismantled,the American railways still account for about 35%of the total length of the world railways,ranking the first in the world.And those demolished railway sub-grades are still retained.The United States of America is a country with the very strong innovation capacity.Once recognizing the advantages of energy-saving and emission-reducing of high-speed railways,the United States of America would catch up with at once.Then the world will trigger a second high tide of highspeed railway constructions.Secondly,the freight transportation structure in America is comparatively reasonable.Railways serve as the first major transport modes.The railways′freight turnover accounts for 41.9% of the total,while highways, 38.7%.Thirdly,in the current urban public transport in the United States,the proportion of rail transit passenger transport has accounted for about half of the total.That is to say,in the American urban public transportation,rail transportation possesses an absolute advantage.Therefore the development of high-speed railway passenger transport would not be unfamiliar to American urban residents.The fourth basis is that more than 100 years ago,the railway constructions in the United States of America had ever set a world record of laying more than 20 000 km railway tracks within a year.

“If we act quickly,we still have a chance to save the world.”This is a popular slogan at the World Climate Change Conference.French friends might be interested in the above story of China's high-speed railways′entering the western region of the United States of America.Let us work together to continue to make more contributions for reducing the global carbon emissions.

(This article is the excerpt of the speech the author made at“The 8th International Sino-French Sustainable Urban Transport Systems Forum”held in Paris on November 26,2015.)

(Translated by Sun Zheng)

Analysis and Solution of Special Axel Counter System Failures

Zhang Hongqiang

AbstractAxle counter system is an important railway signaling equipment,widely used in railway and urban rail transit. By analyzing the failures of Wuxi Metro Line 2 axle counter system on Wuxi Metro Line 2,the reasons of electromagnetic interference in the operating environment of Wuxi metro is elaborated,which generates the axle counter trackside equipment WPOZ faults,a solution of setting the monitoring points in“High Power”mode is proposed,and the testing result shows this fine-tune settings of axle counter trackside equipment can greatly reduce the disturbed chances.

Key wordsmetro;axle counter system;fault;electromagnetic interference

(收稿日期:2015-11-12)

DOI:10.16037/j.1007-869x.2016.02.028

中图分类号U 231.7