低压供电网络暗埋式线路走向识别仪设计

Buried Transmission Line Recognition System in Low Voltage Supply Network

在低压配电网中,暗埋线路因其安全性高、稳定性强和隐蔽性好等特点广泛应用于居民小区等集中供电区域,然而在竣工验收、户表核对等情况下需要确定暗埋线路的走向,目前尚没有在一种不停电、不入户的前提下高效准确识别暗埋线路走向的装置或手段。介绍了一种基于传输线理论的暗埋式线路走向识别仪,利用基于FPGA的DDS信号发生器产生所需特征高频信号,通过信号耦合电路将特征信号注入待测输电线路,特征信号经由作为天线的输电线路进行传播,利用全向接收天线检测沿线有无特征信号来识别出线路的走向。通过分析低压电力线的电磁场特性建立了高频信号在低压电力线中的衰减特性模型,并根据居民楼传输线实际距离模型来排除多径效应对于检测结果的干扰。最后,通过居民楼的实地测试验证了该系统的可靠性。

In low-voltage distribution network,the buried lines are widely used in residential areas because of its high safety,strong stability and good concealment,during the process of final acceptance of the building or household-meter checking,the direction of the buried line need to determined.However,there is no such kind of device or method that can identify the direction of the buried line accurately without power cut and entering households.A buried line direction recognition instrument based on transmission line theory was introduced.The characteristic high frequency signal was generated by DDS signal generator and coupled into the transmission line through signal coupling circuit,then the characteristic signal was transmitted through the transmission line as the antenna,and the omnidirectional receiving antenna was used to detect a characteristic signal along the line to identify the direction of the line.The attenuation model of the low-voltage power line was established by analyzing the electromagnetic field characteristics of high frequency characteristic signal in the low-voltage power line.Distance model of household power lines on different floors was established to eliminate the interference between adjacent lines.Finally,the reliability of the system was verified by the field test in the residential building.