礦山井下IT配電係統絕緣監測的應用

hth下载地址 陳聰

Application of insulation monitoring of IT distribution system in mine

摘要：能源作為經濟發展的重要引擎，堪稱是國民經濟的命脈。采礦業一直是能源工業的重要支柱，我國的礦業生產主要來自井下開采，環境惡劣，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，加上生產環境複雜，易發生惡性事故。出於安全考慮，礦山井下低壓配電係統按規定采用的是IT係統。IT係統就是電源中性點不接地、用電設備外露可導電部分直接接地（PE線）的係統。IT係統的特點是發生第①次接地故障時，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。但此時非故障相對地電壓會升高1.732倍，對線路耐壓要求提升；同時一旦發生二次接地，則構成危險的相間短路，所以須配置絕緣監測裝置，以便在發生第①次接地時就要及時排除隱患。而對於以煤礦為典型代表的井下環境來說，在開采過程中，由於工作場所空間小、縱深長，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、電纜經常發生絕緣強度降低、單相漏電或單相接地故障，不及時處理就可能進一步發展成相間短路。因此，井下作業人員比正常環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，對礦山井下IT係統的實時絕緣監測具有更重要的意義(yi) 。

     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(nei) 外絕緣監測儀(yi) 在線監測現狀

     Online monitoring status of insulation monitors at home and abroad

     我國的電氣設計在建國之初師從(cong) 前蘇聯電氣規範，主要是廣泛的采用TN—C係統，它可以節省一根PE線，比較經濟，但存在很多缺點，如中性線斷裂後設備外殼對地將帶220V危險接觸電壓，不能裝用RCD防電擊等等。改革開放之後我國引進了國際電工學會(hui) 標準，也隨著我國電氣技術的不斷提高，在應用中TN-S、TT、IT係統得到了一定程度的推廣和應用，以IT係統為(wei) 例，在醫療IT方麵目前應用比較成熟，但在很多工業(ye) 場合，由於(yu) 對接地係統的理解和應用尚不盡深入和全方麵，比如煤礦井下場合比較缺乏國產(chan) 絕緣監測裝置就是一個(ge) 證明。目前礦用井下IT係統的絕緣監測裝置以進口品牌為(wei) 主，歐美等發達國家已經較廣泛地在IT配電網絡中應用絕緣檢測技術，而且經過長期的在線運行使發達國家積累了大量監測數據和經驗，這是目前國內(nei) 生產(chan) 廠家需要學習(xi) 和追趕的。

     但采用進口品牌絕緣監測裝置造價(jia) 昂貴，而且人機界麵往往是英文，不利於(yu) 現場人員的使用，在這種背景下，也不斷有國內(nei) 企業(ye) 逐步推出了自己的工業(ye) 用絕緣監測裝置，其中就包括了hth下载地址電氣有限公司的AIM-T係列絕緣監測儀(yi) 。

     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 hth下载地址工業(ye) 絕緣監測儀(yi)

Acrel industrial insulation monitor

AIM-T300

AIM-T500

AIM-T500L

     AIM-T係列絕緣監測儀(yi) 主要應用在工業(ye) 場所IT配電係統中，主要包括AIM-T300、AIM-T500和AIMT500L三款產(chan) 品，均適用於(yu) 純交流、純直流以及交直流混合的係統。

     其中AIM-T300適用於(yu) 450V以下的交流、直流以及交直流混合係統，AIM-T500適用於(yu) 800V以下的交流、直流以及交直流混合係。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係列產(chan) 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係列產(chan) 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

     hth下载地址AIM-T係列工業(ye) 用絕緣監測儀(yi) 目前已經在礦井、紙業(ye) 、船舶、冶金廠等的諸多工業(ye) 場合的IT係統中得到了應用，能夠實時監測係統對地的絕緣狀況，在係統出現絕緣下降或接地故障時，及時報警提醒相關(guan) 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.

參考文獻 Bibliography

1.Solutions for enterprise micro-grid system