Development of cable fault location method using fiber optic distributed temperature sensor

When ground-fault problems occur on a cable line, immediate fault location and restoration are required. Therefore, various new methods to locate the fault point instantaneously have been investigated to replace such conventional methods as the Murray loop method and the pulse radar method [1]. These methods require a long time to locate the fault point. One possible fault location method is to sense the temperature rise following a ground fault using a fiber optic distributed temperature sensor. Application of this method was found feasible through sensing the temperature rise at a ground-fault test using a thermocouple as a temperature sensor with test cables [4]. A power/optical composite cable was prepared experimentally and after verifying its thermal mechanical performance, the temperature rise at an incidence of a fault was determined and the anticipated performance was demonstrated in a ground-fault test. This article describes the outline of the test.     

市内通信电缆绝缘电阻特殊要求的实现和措施

本文对市内通信电缆的各生产过程进行分析、研究和控制 ,从而提出了解决绝缘电阻特殊要求的方法 ,以及改进的措施。     

列车客车用低温发热电缆地面辐射供暖系统的实验研究

对不同地板结构和不同导线间距下发热电缆地面辐射供暖系统的热工性能进行了测试分析，考察了系统的稳定性和可靠性，给出了综合比较结果，分析了影响发热电缆地面辐射供暖系统热工性能的主要因素及其影响规律。     

套管液压式φ106mm密封加固系统研究

针对套管液压式φ100mm密封加固系统在实际应用中的缺点,开展了大通径密封加固技术专题研究.研制的套管液压式φ106mm密封加固器承压达30 MPa以上,悬挂力达到500kN以上,可下入φ100mm小直径分层管柱.现场应用见到了明显的效果,为提高小直径分采分注管柱寿命创造了条件.     

Study on mechanical principle of reinforcing sidewalls and corners of roadway to control floor heave by anchors

The movement principle of sidewalls and floor of extraction opening is analyzed, it is found that floor heave not only has something to do with the floor strata, but sidewalls. The effect of sidewall anchor and corner anchor is studied, the mechanical principle of reinforcing sidewalls and corners is put forward and applied in engineering practice.     

连铸转炉钢包电力牵引车的研制

论述研制连铸转炉钢包牵引车的目的、意义、方案的选择及设计计算校核,对技术要点作出了明确阐述.     

新型二合一液压锚定器的研制

作业起泵过程中常常伴随大量原油、污水落地。目前，各大油田使用的投棒式泄油器成功率较低。为了简化作业管柱．提高工作效率．研制了新型锚定器．并通过计算，确定了该锚定器关键部件的技术参数。经过142井次的使用，证明该二合一液压锚定器既能泄油．减少原油、污水污染．又能锚定管柱，提高泵效，减少检泵周期。     

成都市火车南站斜拉桥斜拉索安装工艺

采用倒链葫芦、卷扬机或软牵引装置对斜拉索进行牵引安装 ,使牵引力达到 5 0 0余kN ,解决了斜拉索安装拉力大这一施工难题。     

The method of testing of XLPE cable insulation resistance to partial discharges and electrical treeing

The paper gives a method of model XLPE medium voltage cable insulation testing for partial discharges and electrical treeing with a point to plane test geometry. Based on this method, a comparative estimate of insulation resistance to treeing and partial discharges have been made. XLPE crosslinked by different methods (steam medium and hot nitrogen medium) and with varying contents of inorganic filler kaolin were tested. The characteristics of partial discharges were measured by means of a pulse height analyser characterized with a microscope. The data have been analysed statistically.     

锚索测力计有关应用问题的探讨

通过分析锚索测力计因受力状态不同而带来的系统误差,提出了测力计实测锚固力的修正方法及部分测力计传感器失效后延续锚固力测值的计算方法.