A Study Of The Monitoring And Anti-theft Of Underground Cable

Underground cables play an important role during power transmission. However, the cables are often suffered from frequent damages(being cut by stolen, etc.) in application due to the backward management methods, as a result of which manufacturing activities will be interrupted and residents daily life will be influenced significantly. Therefore, to study anti-theft and failure detection technologies for underground cables is of great theoretical significance and engineering value.Based on the operation characteristics of underground cables, and according to the underground cables management requirements of the power department, an anti-theft and failure detection system for underground cables is proposed in this paper, which comprises data center server, remote monitoring software and anti-theft device on spot. Real-time monitoring on operation status of underground cables and detection and alarm alerting of cable failures can be achieved with this system. The system has the features of simple structure, low cost and high reliability. Main contents and innovations of this paper are listed as below.1. Problems existed in underground cable maintenance management are analyzed, overall framework of the anti-theft and failure detection system for underground cables is constructed, key techniques and hardware/software designing of system implementation are given, and advantages of the system are summarized.2. Cable failure detection technique based on High-frequency AC signal injection is proposed, in which the high-frequency AC signal is injected into the circuit composed of cable steel armor and the earth, and cable failure can be judged by measuring the voltage in the circuit. This technique overcomes the shortcomings of traditional technologies, and online detection and accurate judgments of cable failures can be realized.3. Based on the research of the principles of signal output, cable monitoring,information sampling and amplification circuits, the hardware device of anti-theft and failure detection is designed by utilizing embedded development and digital circuit technologies. Site acquisition, signal processing, data transmission and telecommunications of cable operation and failure detection data are achieved.4. According to the study of the telecommunication algorithms, handshake program and alarm tracking mechanism, a remote monitoring platform and database management system of anti-theft and cable failure detection is developed based on three-layer C/S structure and database technique. Reception, feedback, display and storage of detection data on spot, and cable failure judgment and cycle alarm are achieved.Main work of this paper has been put into practical application in several power departments. It has been proved that the system can meet the requirements of underground cable operation management, and has significant effects on combating theft of power facilities, maintaining normal operation of the power system, reducing abnormal power interruption and improving the reliability of power transmission and distribution.