With the continuous development of the power system, cable lines play an increasingly important role in the transmission network. Due to the concealment of the cable line, once the fault occurs, it is difficult to carry out the investigation and repair work, so the cable live detection technology came into being, which provides very strong support for the maintenance and overhaul of the cable line. At present, the common methods of cable live detection include infrared thermal imaging method, ultrasonic detection method and electromagnetic induction method, etc., these methods have their own scope of application and limitations, so in practical application, it is not only necessary to select the appropriate method according to the specific situation for detection, but also in order to ensure the accuracy and reliability of the detection results, a variety of methods are also needed to carry out comprehensive detection and analysis, in order to ensure the applicability and effectiveness of cable live detection.
The infrared thermal imaging method judges the live condition of the cable by measuring the temperature distribution on the surface of the cable, which has the advantages of simple operation, wide application range and good real-time performance, but it is also easily affected by external factors such as ambient temperature and solar radiation, thereby affecting the accuracy of measurement; Ultrasonic testing uses the propagation characteristics of ultrasonic waves in the medium to detect internal defects in cables, and is suitable for many types, especially high-voltage cables. However, due to the influence of various factors such as cable material and structure, the propagation of ultrasonic waves may produce attenuation and scattering, which will affect the detection accuracy. In addition to the above methods, there are some other live detection technologies such as high-frequency current method, electromagnetic induction method, etc., and each method has its advantages and disadvantages. Therefore, when choosing a specific method, it is necessary to consider a variety of factors such as testing needs, site conditions, safety factors, and economic costs.
Shaanxi public design and development of a simple operation, intuitive display, easy to carry multi-functional partial discharge live detector, is a set of high-frequency pulse, ultra-high frequency, ultrasonic and transient ground voltage in one of the equipment. Through the combination of intelligent partial discharge detector, HFCT sensor, UHF sensor, contact ultrasonic partial discharge sensor and other components, the measurement and recording, transmission and storage, analysis and exchange of partial discharge signals are realized, and favorable technical support is provided for the on-site measurement of partial discharge. It is suitable for partial discharge detection and diagnosis of a variety of high-voltage power equipment such as cables, switchgears, GIS, transformers, etc.
This article was written by Shaanxi Public Intelligent Technology Co., Ltd. Shaanxi Public Electric Co., Ltd.