礦山井下IT配電系統絕緣監測的應用

摘要：能源作為經(jīng)濟發(fā)展的重要引擎，堪稱(chēng)是國民經(jīng)濟的命脈。采礦業(yè)一直是能源工業(yè)的重要支柱，我國的礦業(yè)生產(chǎn)主要來(lái)自井下開(kāi)采，環(huán)境惡劣，就以煤礦為例，煤礦井下存在水、火、瓦斯、煤塵、頂板五大自然災害，加上生產(chǎn)環(huán)境復雜，易發(fā)生惡性事故。出于安全考慮，礦山井下低壓配電系統按規定采用的是IT系統。IT系統就是電源中性點(diǎn)不接地、用電設備外露可導電部分直接接地（PE線(xiàn)）的系統。IT系統的特點(diǎn)是發(fā)生第①次接地故障時(shí)，接地故障電流僅為非故障相對地的電容電流，其值很小，外露導電部分對地電壓不超過(guò)50V，不需要立即切斷故障回路，因此可以保證供電的連續性。但此時(shí)非故障相對地電壓會(huì )升高1.732倍，對線(xiàn)路耐壓要求提升；同時(shí)一旦發(fā)生二次接地，則構成危險的相間短路，所以須配置絕緣監測裝置，以便在發(fā)生第①次接地時(shí)就要及時(shí)排除隱患。而對于以煤礦為典型代表的井下環(huán)境來(lái)說(shuō)，在開(kāi)采過(guò)程中，由于工作場(chǎng)所空間小、縱深長(cháng)，加上空氣潮濕、多塵、巷道滴水和積水等諸多惡劣因素，很容易引起電纜和電氣設備老化和絕緣電阻下降，從而導致井下設備、電纜經(jīng)常發(fā)生絕緣強度降低、單相漏電或單相接地故障，不及時(shí)處理就可能進(jìn)一步發(fā)展成相間短路。因此，井下作業(yè)人員比正常環(huán)境下更容易遭受電擊的危險，而且還可能導致瓦斯、煤塵的爆炸。

     顯而易見(jiàn)，對礦山井下IT系統的實(shí)時(shí)絕緣監測具有更重要的意義。

     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 .國內外絕緣監測儀在線(xiàn)監測現狀

     Online monitoring status of insulation monitors at home and abroad

     我國的電氣設計在新中國成立之初師從前蘇聯(lián)電氣規范，主要是廣泛的采用TN—C系統，它可以節省一根PE線(xiàn)，比較經(jīng)濟，但存在很多缺點(diǎn)，如中性線(xiàn)斷裂后設備外殼對地將帶220V危險接觸電壓，不能裝用RCD防電擊等等。改革開(kāi)放之后我國引進(jìn)了國際電工學(xué)會(huì )標準，也隨著(zhù)我國電氣技術(shù)的不斷提高，在應用中TN-S、TT、IT系統得到了一定程度的推廣和應用，以IT系統為例，在醫療IT方面目前應用比較成熟，但在很多工業(yè)場(chǎng)合，由于對接地系統的理解和應用尚不盡深入和全方面，比如煤礦井下場(chǎng)合比較缺乏國產(chǎn)絕緣監測裝置就是一個(gè)證明。目前礦用井下IT系統的絕緣監測裝置以進(jìn)口品牌為主，歐美等發(fā)達國家已經(jīng)較廣泛地在IT配電網(wǎng)絡(luò )中應用絕緣檢測技術(shù)，而且經(jīng)過(guò)長(cháng)期的在線(xiàn)運行使發(fā)達國家積累了大量監測數據和經(jīng)驗，這是目前國內生產(chǎn)廠(chǎng)家需要學(xué)習和追趕的。

     但采用進(jìn)口品牌絕緣監測裝置造價(jià)昂貴，而且人機界面往往是英文，不利于現場(chǎng)人員的使用，在這種背景下，也不斷有國內企業(yè)逐步推出了自己的工業(yè)用絕緣監測裝置，其中就包括了安科瑞電氣有限公司的AIM-T系列絕緣監測儀。

     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(yè)絕緣監測儀

Acrel industrial insulation monitor

AIM-T300

AIM-T500

AIM-T500L

     AIM-T系列絕緣監測儀主要應用在工業(yè)場(chǎng)所IT配電系統中，主要包括AIM-T300、AIM-T500和AIMT500L三款產(chǎn)品，均適用于純交流、純直流以及交直流混合的系統。

     其中AIM-T300適用于450V以下的交流、直流以及交直流混合系統，AIM-T500適用于800V以下的交流、直流以及交直流混合系。AIM-T500L則是相比AIM-T500增加了絕緣故障定位功能。

     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系列產(chǎn)品的技術(shù)參數如下表所示：

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

2）AIM –T系列產(chǎn)品的典型應用如下圖所示：

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

4 小結Summary

     安科瑞AIM-T系列工業(yè)用絕緣監測儀目前已經(jīng)在礦井、紙業(yè)、船舶、冶金廠(chǎng)等的諸多工業(yè)場(chǎng)合的IT系統中得到了應用，能夠實(shí)時(shí)監測系統對地的絕緣狀況，在系統出現絕緣下降或接地故障時(shí)，及時(shí)報警提醒相關(guān)人員排查故障，在應用中起到了很好的監控和預防效果。

     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.

編輯：安科瑞 孫斌

公司：江蘇安科瑞電器制造有限公司