Power cables play a crucial role in the power transmission system. However, cable failures often pose a threat to the stable operation of the power system, leading to power outages and economic losses. In order to timely detect and solve cable faults, ensure the reliability and safety of the power system, various detection methods and technologies have emerged. Asia Cable will explore several major power cable fault detection methods and their technical principles.

Infrared imaging technology

Infrared imaging technology utilizes the temperature anomaly characteristics of cable fault points to capture temperature distribution images of cable surfaces through infrared cameras. Due to the local overheating phenomenon that usually occurs at cable fault points, infrared imaging can quickly and non-contact detect these abnormal temperature points.

The advantage of infrared imaging lies in its non-contact and real-time monitoring ability, which is suitable for online detection. However, this technology can only detect surface temperature anomalies and cannot accurately locate internal fault points, and is greatly affected by external environmental temperatures.

Bridge testing method

The bridge test method determines the fault location by measuring the resistance changes at both ends of the cable. Common methods include Wheatstone bridge and Megohmmeter testing. By comparing the resistance values of normal cables and faulty cables, the fault point can be accurately located.

The advantage of the bridge testing method is high testing accuracy, which can accurately locate internal faults in cables. But this method requires power-off operation, which is not suitable for online detection, and the testing process is relatively complex.

partial discharge detection

Partial discharge detection technology is used to detect partial discharge phenomena in cable insulation systems. By monitoring the signals of partial discharge, the insulation performance of the cable can be evaluated and the discharge location can be located.

This technology can detect insulation issues in the early stages of cable faults and has high sensitivity. However, the detection equipment is complex, the testing conditions are high, and it is easily affected by external interference signals.

There are various methods for detecting power cable faults, each with its own advantages and disadvantages. Infrared imaging technology is suitable for fast, non-contact surface detection, bridge testing, and partial discharge detection, and has advantages in evaluating insulation performance. The selection of appropriate detection methods should be comprehensively considered based on factors such as cable type, fault nature, and on-site conditions to improve detection efficiency and accuracy.