The Application Research On Intelligent Temperature Monitoring System Of Power Cable In Zigong 110kV Daoshenghao Substation

With the rapid development of power grids, due to oil-free, less ancillary equipment, as well as the installation and operation maintenance are simple, XLPE power cable has been widely used. As a simple cable insulation condition monitoring method, cable temperature monitoring will help to identify power cable insulation defects, to prevent accidents and ensure the safe operation of the cable.In this paper, based on a comprehensive analysis of domestic and international cable temperature monitoring technologies and methods, makes a deep research on the mathematical models of the relationship between core temperature and surface temperature, and design of the hardware, software of the on-line monitoring system, as well as on-site installation programs and other issues.①The system adopts finite element method, and uses COMSOL Mutiphysics software to establish a math model for relation between interior temperature and exterior temperature of XLPE cable joint, and the model makes a theoretical and experimental analysis for the VYJV22-6/10kV 3×300 XLPE cable, to verify the validity and accuracy of the model, which provide a theoretical and experimental basis for monitoring the core temperature of XLPE cable.②Adopting distributed control system, it completed hardware design of the XLPE cable temperature on-line monitoring system. The design of on-line monitoring system includes for parts: temperature sensors, real-time temperature collecting units (sub-stations), fiber-optic ring network communications, and the computer workstation. The system has many advantages, such as simple structure, high reliability, strong scalability, and easy installation and maintenance and so on.③According to the specific requirements for the XLPE cable on-line temperature monitoring system, the paper proposed design thought of monitoring system software, and gives the overall software design diagram. On-line monitoring system applications programs including sub-station software, workstation software and communications software, it also gives the flow chart of data sampling, data processing, data receiving, sending and so on. The software system provides an intuitive, simple data display and system control interface for operators and managers.④According to the actual situation of 110kV Daosheng Hao substation, it determined the on-site installation program of cable temperature on-line monitoring system and completed the on-site installation and trial operation. The trial operation data of the monitoring system shows: the system operates stably; The monitoring data reflect the changes of cable temperature follows the load changes in a timely manner. It ensures the safe operation of the cable.