In April 2020, it completed the lightning protection and grounding transformation of the new energy generation branch of the State Power Investment Group Jiangxi Electric Power Co. After the completion of the renovation, the owner unit took the initiative to publicize it in the group newspaper.
The project changed the traditional thinking of only investigating, testing and transforming the lightning strike point and grounding resistance after encountering a lightning strike trip accident in the past, and conducted an in-depth analysis for the lightning strike problem and a comprehensive and detailed investigation and study of the entire line pole tower in addition to the grounding resistance. Analysis of the soil resistivity and soil environment distribution, pole tower wiring, lightning arrester performance, line pole tower within the grounding network structure and conductivity, in addition, combined with lightning strike data, from the perspective of high frequency impact and ideas for a comprehensive analysis, and according to the results of the analysis proposed a targeted transformation program.
This project also adopts the flexible grounding modification technology to reshape and modify the grounding network structure of the whole line grounding pole. The core of this technology is to redesign and reform the grounding network for the characteristics of natural drift that occurs in the grounding network under the effect of high frequency impact. The new grounding network structure after adopting this technology has very low corrosion rate, very low impact change rate, very low resistivity and very strong stability, which brings high level of stable safety performance and longer service life to the engineering grounding system. The technology makes the grounding network not only has good grounding conduction performance in the working frequency state, but also can complete the lightning charge conversion excellently under the lightning high frequency impact condition, and absorb the energy fully in a very small range, so that the grounding network can maintain a safe and stable voltage level under the lightning impact, effectively avoiding a series of follow-up problems brought by overvoltage backlash. This is the effect that any other traditional technology does not have, and is very economical and applicable.
This project also adopts the flexible grounding modification technology to reshape and modify the grounding network structure of the whole line grounding pole. The core of this technology is to redesign and modify the grounding network in response to the characteristics of natural drift of the grounding network under the action of high frequency impact. The new grounding network structure after adopting this technology has very low corrosion rate, very low impact change rate, very low resistivity and very strong stability, which brings high level of stable safety performance and longer service life to the engineering grounding system. The technology makes the grounding network not only has good grounding conduction performance in the working frequency state, but also can excellently complete the lightning charge conversion under the lightning high frequency impact condition, and fully absorb the energy in a very small range, so that the grounding network can maintain a safe and stable voltage level under the lightning impact, effectively avoiding a series of follow-up problems brought about by overvoltage backlash. This is the effect that any other traditional technology does not have, and it is very economical and applicable.
Project transformation
After our intervention, we first conducted a full-field survey, retrieved the accident analysis report, recorded the waveform, and invited a professional third-party company to conduct full-field testing and data analysis together, including resistivity distribution analysis, grounding resistance analysis, equipotential analysis, excess resistance difference analysis, arrester data analysis, arrester wiring method exclusion, impact resistance reduction calculation and analysis.
In January 2020 to determine the transformation program, from the arrester selection, wiring design, grounding structure transformation in three aspects of technical transformation work. April 2020 after the completion of the transformation operation so far, the whole line is running smoothly, without a lightning trip accident, the State Power Investment Jiangxi New Energy Company internal unanimous approval and praise.
After the transformation, the operation has not occurred again for more than a year of lightning tripping, verifying the effectiveness of the work of both sides, confirming the accuracy of the judgment of the problem, taking the right measures, and achieving satisfactory results. At present, the line not only runs stably, but also saves a lot of maintenance costs for the country, and also greatly reduces economic losses.
Flexible grounding body technology introduction
Flexible grounding body technology is an emerging grounding technology with national invention patent and U.S. invention patent, using new materials and advanced grounding network formation method. Flexible grounding body is a new type of grounding body material composed of non-metallic conductive material, electrolyte material, anti-corrosion factor and structural material. It has the remarkable advantages of excellent safety performance and resistance reduction effect, remarkable anti-corrosion factor and convenient use steps as well as wide applicability. From the material molecular structure level, the charge storage and lightning current discharge capacity is significantly improved, and the frequency and impact grounding resistance is significantly reduced.
Flexible grounding technology solves this problem
High grounding resistance
Lightning strikes on transmission lines tripping
High voltage burnout of equipment
Severe corrosion in harsh environments