On-line Monitoring System For The Insulation Aging Of XLPE Cable

With the development of industry, there is a growing demand for electricity in modern production and life. The roles of XLPE cable are more important in daily power transmission projects. As XLPE cable heavily used, there has been a growing number of cable accidents. As a result, the effective detection methods of cable insulation aging become an urgent need to solve by the relevant departments. As the invested cables are in different ages, their insulation aging are in various levels.In that case, there is an urgent requirement to find a method to monitor the cables’ aging insulation. So we can able to forecast real-time situation and predict the developing insulation direction of XLPE cables in advance.Firstly, the article has a reliable comparison and analyze for the current mainstream on-line cable fault detection, and ultimately determines the DC component method as the final use of this project. Then it analyzes the murderer of cable insulation aging-- Water tree, introduceing the mechanism and cause of water tree’s production, and puts forward some methods to prevent it. On this basis, it designs the structure of hardware and software for the cable on-line monitoring system. In terms of hardware, we design the signal of acquisition module, filter module, amplification module, A/D converter module. After the completion operation of the above modules, we use the serial communication method as the way of data transmission, and complete the design of HMI monitoring data showed on the PC through Kingview. As a result, you can observe the signal features of cable insulation aging directly, and we accomplish to show the cable leakage signal in real-time display by King-view, achieving the expectation of real-time monitoring for the cable insulation.In this paper, the XLPE on-line monitoring system is to measure the weak DC signal to the earth from the insulation layer in the case of on power. It reduces the electromagnetic interference by maximum extent from outside through the power-filter and without power-filter, ensuring the extraction and measurement of the target signals. The monitoring system uses a 12 bits high precision A/D conversion module, designing a serial communication method as the way of data transmission, realizeing the HMI design on a PC through Kingview. And finally it accomplishes a practical modular cable monitoring system. these researches are an in-depth exploration for the routine cable on-line monitoring fields.