計軸系統特殊故障的分析與解決方案

張宏強(無錫地鐵集團有限公司建設分公司,214023,無錫∥工程師)

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計軸系統特殊故障的分析與解決方案

張宏強
(無錫地鐵集團有限公司建設分公司,214023,無錫∥工程師)

摘 要計軸系統是一種重要的軌道交通信號設備,廣泛應用于鐵路、城市軌道交通領域。以無錫地鐵2號線計軸系統故障為例,分析了在2號線運營環境下的電磁干擾對計軸軌旁設備產生“脈沖不計數”故障(WPOZ)的原因,提出了設置檢測點至“高功率”模式的解決方案。測試結果表明,所推薦的檢測點設置方法可大幅度降低受擾機率。

關鍵詞地鐵;計軸系統;故障;電磁干擾

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

無錫地鐵2號線計軸系統在調試期間出現了相關區段受擾故障頻發的問題。本文討論該故障的成因并錄求解決方案。

1　計軸系統

1.1計軸系統功能

計軸設備是通過安裝在所監測軌道區段兩端的計軸軌道傳感器,對駛入與駛出該區段的列車軸數進行計算,從而完成對該區段空閑與占用狀態的判斷。當列車完整出清區段后,區段表示為空閑,否則表示為占用。作為區段狀態檢查的信號設備,計軸設備的作用和軌道電路等效。

1.2AzLM計軸系統的構成

Az LM計軸系統包括室內設備和室外設備兩部分。室內設備主要為安裝在封閉機柜中的計軸評估器(ACE),室外設備為計軸檢測點。圖1位Az LM計軸系統構成示意圖。

圖1　Az LM計軸系統構成示意圖

1.3Az LM計軸系統工作原理

圖2為Az LM計軸系統解決方案示意圖。

圖2　Az LM計軸系統解決方案示意圖

(1)軌道磁頭(車輪傳感器):由兩個安裝在同一根鋼軌上的物理偏移線圈裝置Sk1和Sk2組成。軌道外側是兩個Tx線圈,軌道內側為兩個Rx線圈,產生約為30 k Hz的不同頻率的兩種信號,在軌道附近形成電磁場。這些裝置提供了兩個時間偏移的感應電壓,利用這些裝置就可以在電子單元中確定輪軸是否通過以及輪軸的行駛方向,因為基于可靠性原因,磁頭中除線圈外不存在其他電子部件。

(2)車輪電子檢測盒(EAK):電子單元E-ES 30 H為Tx發送磁頭供電,檢測并計算輪軸脈沖,監控磁頭,進行自檢并向室內主機ACE發送包含計數和監控信息的報文。計數、監控和報文生成功能由兩個受計軸主機安全模塊監控的獨立微控器執行。

(3)室內計軸評估單元:通過評估室外計軸區段計入及計出的軸數來判斷區段是否空閑。

2　計軸系統故障分析

無錫地鐵2號線全線采用了Az LM計軸系統,自列車上線調試以來計軸單點受擾故障頻發,統計數據顯示計軸故障累計發生30余次,涵蓋全線多個集中區。

通過定期搜集計軸的診斷文件,以預估潛在的問題,并對全線計軸安裝、關聯設備及數據參數進行現場檢查和分析,初步得出以下結論:故障發生在列車進站或道岔前;計軸本身質量、安裝及軟件配置沒有問題;故障與附近接地、雜散電流環境無關;與聯鎖系統接口無關;受影響的計軸部件位于室外磁頭與軌旁安裝盒之間,與室內設備無關。

通過調研國內主要地鐵城市計軸系統運行與故障情況,未發現類似故障,該故障類型屬國內首例新的計軸故障。

為找出故障的根本原因,使用示波器進行現場測量,以撲捉故障波形。檢測設備(帶有記錄功能的示波器)安裝在映月湖公園站的檢測點AC204J處(站臺入口檢測點)。與該檢測點相對應的ACE安裝在查橋站。所有的檢測點采用雙線標準ISDN(綜合業務數字網)連接至遠程電源。示波器設置方式為:對預定義閾值范圍內的所有模擬信號進行記錄,評估板的數字器做平行評估記錄,以與診斷信息中的事件同步。

此次測試歷時超過60 h,共記錄經過列車300余列。圖3顯示其中有60多列列車產生電磁干擾信號,5列列車使區段受擾。

在對檢測結果進行評估后發現,EMI干擾的唯一來源是車輛。列車的第一節和最后一節車廂從未發生過干擾。有時只有一節車廂(主要是第二節車廂),但也有兩節或三節車廂發生干擾的情況。沒有發現其他特殊案例。由此可以假定,產生EMI干擾的車廂號取決于列車運營方式和系統特定條件。圖4是車廂數量與干擾數量的記錄。因為有些情況下是一節以上的車廂產生EMI干擾,干擾現象的總數與產生干擾的車廂數量并不一致。

圖3　檢測列車數量

圖4　產生EMI干擾現象的車廂數量

作為區段干擾的主要原因,識別出一種故障現象,系統定義為WPOZ(脈沖不計數)。每當電子單元的評估板檢測到一個不能被識別為正確車輪脈沖的電磁脈沖時,就會產生此診斷信息。當一個檢測點兩個磁頭中的任意一個受影響時就會出現這種情況。因為這種情形無法與磁頭失效進行區分,基于安全考慮將檢測點設置為受擾狀態。產生這種錯誤的車輪脈沖的條件為:至少一個磁頭在磁頭工作頻率范圍(約30 k Hz)內受電磁干擾影響;脈沖的幅值達到足夠高值,足以產生數字脈沖,且數字脈沖長于4 ms。

根據統計分析,選擇在WPOZ出現次數最多的檢測點進行測量(在映月湖公園站進站口檢測點AC204J)。分析進一步表明:不是2號線所有檢測點都受到相同強度的影響,故障現象(報出WPOZ)主要集中在進站口或在岔道前區域內,區間的檢測點則不受影響;干擾與列車的運行有關。圖5為一列有電磁干擾列車的采集波形。

3　計軸系統故障解決措施

為了避免該不明干擾,決定通過增加磁頭的信噪比提高抗干擾能力。計軸《ZP30H安裝調試手冊(V2.0)》中4.4描述“這個特性對于3CR01836AEAA或更新的模擬板可用。在特殊應用中,發送磁頭的供電可以通過將模擬板上的開關S3打在位置2來提高。這樣會產生更好的信噪比,但是會降低軌旁電纜的最大允許阻抗。”

圖5　一列有電磁干擾列車的采集波形(原檢測點設置)

圖6　一列有電磁干擾但沒有引起WPOZ列車的采集波形(調整參數設置后的檢測點)

通過設置檢測點至“高功率”模式(出廠默認值是“正常功率”),車輪通過所產生的脈沖幅值可提高25%。這允許對磁頭進行調整以進一步增加信噪比。“高功率”的設置是另一種出廠默認設置的選項,是系統允許的一種設置。

通過示波器檢測試驗,并對測量設備加以調整,通過對調整后檢測數據的統計分析,以及對日志文件的分析進行辨別,未發現有干擾達到檢測點的觸發值,從而導致無效輪脈沖的產生。測試顯示該調整措施是成功有效的。圖6為調整參數設置后,一列有電磁干擾但沒有引起WPOZ列車的采集波形。

4　結語

通過現場測量捕捉到了一種新的計軸系統故障的源頭,該故障都發生在列車運行過程中并存在于列車車廂中部。通過設置檢測點至“高功率”模式,提高信噪比,干擾的概率大幅減小,徹底避免來自于車廂中部的不明干擾。

參考文獻

[1] 北京泰雷茲交通自動化控制系統有限公司.Az LM工程手冊(3CR01800xxxx GAAFQ)[G].北京:北京泰雷茲交通自動化控制系統有限公司,2014.

[2] 北京泰雷茲交通自動化控制系統有限公司.ZP 30 H安裝指南(3CR01820Axxx583QQ)[G].北京:北京泰雷茲交通自動化控制系統有限公司,2014.

[3] 北京泰雷茲交通自動化控制系統有限公司.Az LM型計軸系統產品說明書(V3.0)[G].北京:北京泰雷茲交通自動化控制系統有限公司,2014.

[4] 高玉,王洪波.基于狀態機的計軸處理模型研究[J].城市軌道交通研究,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

中圖分類號U 231.7