The main purpose of corona ring coil is to suppress the corona discharge phenomenon of high-voltage equipment and protect the insulation system of the equipment from the root cause. In the insulator strings, cable terminals, GIS equipment and other parts of high-voltage transmission lines, due to uneven distribution of electric fields, corona discharge will be caused when the electric field strength on the surface of the conductor is too high. This kind of weak discharge, which is imperceptible to the naked eye, will produce corrosive gases such as ozone and nitrogen oxides. Under long-term action, it will accelerate the aging of the insulator skirt and the cracking of the cable insulation layer, which will eventually lead to the breakdown of the insulation of the equipment and cause power outages. Traditional solutions such as increasing the radius of the conductor and applying anti-halo coatings either have poor adaptability or are prone to failure in harsh environments and cannot form long-term protection. Our corona ring coil adopts a high-strength alloy one-piece molding process. Through the optimized arc structure design, the locally excessive electric field strength of the equipment can be evenly dispersed to the surface of the ring body, so that the electric field distribution tends to be gentle, and the generation of corona discharge is fundamentally avoided.
The secondary purpose of corona ring coil is to reduce energy loss and electromagnetic interference and improve the overall energy efficiency of the transmission system. This purpose has obvious effects in ultra-high voltage and ultra-high voltage projects. Corona discharge can cause loss of electrical energy. According to statistics from the international power industry, there are no high-voltage lines with corona ring coil installed. The annual loss of electrical energy due to corona accounts for 0.5% to 2% of the total transmission capacity of the line. For ultra-high-voltage lines with an annual transmission capacity of 10 billion degrees, this means a waste of tens of millions of degrees of electrical energy. At the same time, corona discharge will also produce high-frequency electromagnetic radiation, interfere with peripheral communication signals, radar equipment, and even affect the normal operation of precision instruments. Through precise electric field optimization design, our corona ring coil can not only completely suppress the visible corona, but also minimize the invisible weak corona loss. In addition, the surface of the corona ring coil has undergone special passivation treatment, which can effectively reduce the intensity of electromagnetic radiation, fully comply with the relevant standards of the International Electrotechnical Commission on electromagnetic compatibility, and avoid interference with peripheral equipment. For transmission projects close to airports and communication base stations, it is an important guarantee for project compliance.
In addition, the use of corona ring coil in simplifying the operation and maintenance process and reducing long-term operating costs is in line with the pursuit of project economy by B-side buyers. Traditional anti-corona products, such as split structures, have complex installation and easy loosening due to vibration. Frequent inspections and maintenance are required in the later stage, which increases labor and time costs. There are also some low-cost products that use inferior steel, which are prone to corrosion in coastal salt spray areas and industrial polluted areas, and need to be replaced in 3 to 5 years, which drives up the cost of the whole life cycle. Our corona ring coil adopts an integrated and seamless design, without complicated splicing, workers only need to use conventional tools to complete the installation, and the installation time of a single group can be shortened to less than 30 minutes. At the same time, the ring body is made of alloy material with strong weather resistance, and the surface is specially treated to maintain stable performance for a long time in harsh environments such as coastal, high humidity, and industrial pollution, greatly reducing the investment in late inspection and replacement.