Application of insulation monitoring of IT distribution system in mine

摘要：能源作(zuo)為經濟發展的(de)重要引擎(qing)，堪稱是(shi)國民經濟的命脈(mo)。采礦(kuang)業一直是能(neng)源工(gong)業的重要支柱，我國(guo)的礦(kuang)業生產主要來(lai)自井下開采，環(huan)境惡劣，就(jiu)以煤礦(kuang)為例，煤礦(kuang)井下存在水、火、瓦斯(si)、煤塵、頂(ding)板五大自然災害，加上生產環(huan)境復雜，易(yi)發生惡性事故(gu)。出(chu)于安全考(kao)慮，礦山井下低壓配電系統按規定(ding)采(cai)用的(de)是IT系統。IT系統就是電源中性點不接地(di)(di)、用電設備外露可導電部(bu)分直接接地(di)(di)（PE線(xian)）的(de)系統。IT系統的(de)特點是發生第①次接(jie)地故障(zhang)時，接(jie)地故障(zhang)電(dian)流僅為(wei)非故障(zhang)相對(dui)地的(de)電(dian)容電(dian)流，其值(zhi)很小，外露(lu)導電部分對地電壓(ya)不超過50V，不需要(yao)立即切(qie)斷故障回路，因(yin)此可以保證供(gong)電的(de)連續性(xing)。但(dan)此時非故障相對(dui)地電(dian)壓會(hui)升高1.732倍，對線路耐壓要求提升；同時一旦發生(sheng)二(er)次接地，則構成(cheng)危險的相間短路，所(suo)以須配置(zhi)絕緣(yuan)監測裝置(zhi)，以便在(zai)發生(sheng)第①次(ci)接(jie)地時就要及時排除(chu)隱(yin)患。而對(dui)于(yu)以煤礦為典(dian)型代表的井(jing)下環境來(lai)說，在開采過程中，由于(yu)工作(zuo)場所空間小(xiao)、縱(zong)深長(chang)，加上空氣(qi)潮濕、多塵、巷(xiang)道滴水和積水等(deng)諸多惡劣因素，很(hen)容易引起(qi)電纜(lan)和電氣(qi)設(she)備老化和絕緣電阻下(xia)(xia)降，從而導致(zhi)井下(xia)(xia)設(she)備、電纜(lan)經常發(fa)(fa)生絕緣強度降低、單相漏(lou)電或單相接地故障，不及(ji)時(shi)處理就可能進一步(bu)發(fa)(fa)展(zhan)成相間短路。因此，井下(xia)(xia)作業人員(yuan)比正常環境下(xia)(xia)更容易遭受電擊(ji)的(de)危(wei)險，而且還可能導致(zhi)瓦斯、煤塵的(de)爆炸。

    顯(xian)而易見，對礦山井下IT系統的實時絕緣監測具(ju)有(you)更(geng)重要的意義。

    As we all know, energy is an important engine of economic development and it is also the lifeblood of the national economy. The mining industry has always been the important pillar of the energy industry. China’s mining production mainly comes from underground where the environment is harsh.For example, there are five natural disasters: water, fire, gas, coal dust, and coal seam roof. In addition, the production environment is complex and it’s easy to cause the fatal accidents.

    For safety reasons, the low-voltage power distribution system in the mine adopts an IT system. It is a system that neutral is ungrounded and conductive part of the load is directly grounded (PE line). The features of the IT system is that when the first grounding fault occurs, the current of grounding fault is very small, the voltage of exposed conductive part to ground is below 50V, It is unnecessary to cut off the fault circuit immediately, so it can ensure the continuity of power supply. But at this time, the voltage of non-fault relative to ground will increase by 1.732 times, and the requirement for line withstand voltage will increase. At the same time, once a secondary grounding occurs, it will lead to a dangerous phase-to-phase short-circuit, so an insulation monitoring device should be installed which can help eliminate hidden dangers in time when the first grounding occurs.For the coal mine as the typical representative of underground environment , in the process of mining, due to limited space, long in depth, humid air, dustiness, waterlogged roadway, and many other adverse factors, it is easy to cause the cable insulation resistance and electric equipment aging and decline, the underground equipment and cables often suffer from insulation strength reduction, single-phase leakage or single-phase grounding fault, If not handled in time, it may further develop into phase to phase short circuit. As a result, Underground workers are more vulnerable to electric shock than they would be in a regular environment, and may also cause explosion of gas and coal dust.

    Obviously, It has more important significance for the real-time insulation monitoring of mine IT system.

2 .國內外絕緣(yuan)監測(ce)儀在線監測(ce)現狀

    Online monitoring status of insulation monitors at home and abroad

    我國的電(dian)氣(qi)設(she)計在(zai)新中國成立之初師(shi)從前蘇聯(lian)電(dian)氣(qi)規范，主(zhu)要是廣泛的采(cai)用TN—C系統，它可以節(jie)省一(yi)根PE線，比較經濟，但存在(zai)很多缺點，如(ru)中性(xing)線斷裂后設(she)備(bei)外(wai)殼對(dui)地(di)將帶220V危險接(jie)觸電(dian)壓，不能裝(zhuang)用RCD防(fang)電(dian)擊等等。改革開放(fang)之后(hou)我國引進(jin)了國際(ji)電工學會標準(zhun)，也隨著(zhu)我國電氣技術的不(bu)斷提高，在(zai)應(ying)用中(zhong)TN-S、TT、IT系(xi)(xi)統得到了一(yi)定程度的推廣和(he)應用，以IT系(xi)(xi)統為(wei)例，在醫療IT方(fang)面目(mu)前應用比較成熟(shu)，但在很多工業場(chang)合，由于(yu)對接地系(xi)(xi)統的理解和(he)應用尚不盡深入和(he)全方(fang)面，比如(ru)煤礦井下場合比較缺(que)乏(fa)國產絕緣監測(ce)裝(zhuang)置就是(shi)一個證明(ming)。目前礦用井下IT系統的(de)絕緣監測(ce)裝(zhuang)置以進(jin)口品牌為主，歐美(mei)等發達國(guo)家已經較(jiao)廣泛地(di)在(zai)IT配電網絡(luo)中應用絕緣檢測(ce)技術，而且經過長(chang)期(qi)的(de)在(zai)線運行使發達國(guo)家積(ji)累(lei)了(le)大量監測(ce)數據和(he)經驗，這是目前國(guo)內生產廠家需要學習(xi)和(he)追趕(gan)的(de)。

    但采用(yong)(yong)進口品牌絕(jue)緣監測(ce)裝(zhuang)置(zhi)造價昂貴，而且(qie)人(ren)機界面(mian)往往是英文(wen)，不利(li)于現(xian)場人(ren)員的使(shi)用(yong)(yong)，在這種背景下，也不斷有國內企業逐步推(tui)出了(le)自己的工業用(yong)(yong)絕(jue)緣監測(ce)裝(zhuang)置(zhi)，其中就包括了(le)安科(ke)瑞電氣有限公司的AIM-T系列絕緣監(jian)測儀。

    At the beginning of the founding of the People's Republic of China, China's electrical design was based on the former Soviet Union's electrical code, mainly using TN-C system . It can save a PE line, which is more economical, but there are many disadvantages, such as, after the neutral line breaks, the equipment shell to the ground will have a dangerous contact voltage of 220 V, and RCD cannot be installed to prevent electric shock, etc. After the reform and opening up, China has introduced the standards of IEC, and with the continuous improvement of electrical technology in China, TN-S, TT and IT systems have been promoted and applied to a certain extent. For example, the application in medical IT is relatively mature at present, but in many industrial occasions, due to the understanding and application of grounding system is not thorough and comprehensive, for example, the lack of domestic insulation monitoring device in coal mine is a proof.At present, the insulation monitoring devices of mine underground IT system are mainly imported brands.Insulation detection technology have been widely used in IT distribution network in developed countries such as Europe and the United States. And they have accumulated a lot of monitoring data and experience after a long-term online operation. This is what domestic manufacturers need to learn and catch up with.

   However, it is expensive to use imported brand insulation monitoring devices, and the human-computer interface is often in English, which is not conducive to the use of field workers. There are also domestic enterprises which have gradually launched their own industrial insulation monitoring devices, including the AIM-T series insulation monitoring devices of Acrel.

3 安科瑞工業(ye)絕(jue)緣監測儀

Acrel industrial insulation monitor

AIM-T300

AIM-T500

AIM-T500L

    AIM-T系列絕緣(yuan)監測儀主要(yao)應用(yong)在工業(ye)場所IT配電系統中(zhong)，主要(yao)包(bao)括AIM-T300、AIM-T500和AIMT500L三款產品，均(jun)適用(yong)于(yu)純(chun)交流、純(chun)直流以及交直流混(hun)合的(de)系統。

    其(qi)中(zhong)AIM-T300適(shi)用(yong)于450V以(yi)(yi)下(xia)的交流、直(zhi)流以(yi)(yi)及(ji)交直(zhi)流混合(he)系(xi)統(tong)，AIM-T500適(shi)用(yong)于800V以(yi)(yi)下(xia)的交流、直(zhi)流以(yi)(yi)及(ji)交直(zhi)流混合(he)系(xi)。AIM-T500L則是相(xiang)比AIM-T500增加了絕緣故障定位(wei)功能。

    AIM-T series insulation monitor is mainly used in IT power distribution system of industrial site, including AIM-T300, AIM-T500 and AIM-T500L, which are all applicable to pure AC, pure DC and AC / DC hybrid systems.

    AIM-T300 is suitable for AC, DC and AC / DC hybrid systems below 450V, and AIM-T500 is suitable for AC, DC and AC / DC hybrid systems below 800V. AIM-T500L has the function of insulation fault location compared with AIM-T500.

1）AIM –T系(xi)列產品的技術參數如下表所示：

The technical parameters of AIM-T series products are shown in the table below

2）AIM –T系(xi)列產品(pin)的(de)典(dian)型應用如(ru)下圖所示：

The typical application of aim-t series products is shown in the following figure:

4 小結Summary

    安科瑞AIM-T系(xi)(xi)列工業(ye)(ye)用絕緣(yuan)監(jian)(jian)測儀目前已經在礦井、紙業(ye)(ye)、船舶、冶金廠等(deng)的(de)(de)諸多工業(ye)(ye)場合的(de)(de)IT系(xi)(xi)統(tong)中得(de)到(dao)了應(ying)用，能夠實時監(jian)(jian)測系(xi)(xi)統(tong)對地的(de)(de)絕緣(yuan)狀況，在系(xi)(xi)統(tong)出現絕緣(yuan)下降或接地故(gu)(gu)障時，及(ji)時報(bao)警(jing)提醒相關人員(yuan)排(pai)查故(gu)(gu)障，在應(ying)用中起到(dao)了很好(hao)的(de)(de)監(jian)(jian)控和預防效果(guo)。

    At present, Acrel AIM-T series industrial insulation monitor has been applied in the IT system of many industrial occasions, such as mine, paper industry, ship, metallurgy plant, etc. It can monitor the insulation condition of the system to the ground in real time. When the system has insulation drop or ground fault, it can alarm and remind relevant person to check the fault, which has a good monitoring and prevention effect in the application.

參考文獻 Bibliography

1.Solutions for enterprise micro-grid system