The Study Of Lightning Protection Technology For The New Generation Doppler Weather Radar Station

Lightning is a kind of discharge phenomenon that occurs frequently in nature. Because it has much physical effect, such as strong electronic current, high temperature, violent shock wave, and strong electromagnetic radiation and so on, lightning can produce tremendous detrimental effect in an instant and constitute a serious threat to people's lives and property safety. Lightning disaster has been listed as "one of the ten most serious natural disasters" by the United Nations departments. As a result of lightning danger is all-pervasive, so far human beings have not grasped the way to avoid lightning fully.The principles of modern lightning protection technology are all terrain grade, comprehensive treatment, quality inspections at all levels, which has been taken as a systematic project. The basic principle is to provide a reasonable low-impedance discharge path to the earth for lightning (including the lightning electromagnetic pulse radiation), rather than let it choose random discharge channel. That is to say, it must control the discharge and conversion of lightning energy. Comprehensive lightning protection technology is usually adopted.Comprehensive protection system against lightning is designed for the new generation Doppler weather radar in Zhangbei,external and internal lightning protection measures are combined coordinating and unifying, making it safe and feasible, advanced technology, economic rationality as possible.This paper studies the form of lightning, the harm it carries, the mode it strikes in and the characteristic of lightning current. The results show that direct and indirect attacks from lightning are the main sources which put the new generation Doppler weather radar in danger. Thus, illustrated by the case of the new generation Doppler weather radar station in Zhangbei, according to the position, the climate and the using characteristic, taking GB50057-94(2000)《Code for design of lightning protection of buildings》as reference and combine with GB50343-2004《Technical code for protection against lightning of building electronic information system》, the risk evaluation on direct attacks and electromagnetism impulse from lightning is carried out,and the design is made. The conclusions are as follows:①The radar station belongs to the second species lightning protection building,the lightning electromagnetic impulse protection grade of radar system belongs to A.②Based on electromagnetic compatibility principle, buildings or structures of the radar station are divided into different areas of the lightning protection from outside to inside according to protected space(LPZ) to determine the intensity of lightning electromagnetic pulse at different spaces and adopt according preventive measure.③To optimize the amount and the position of lightning rod ,three lightning rods of the same tallness are installed in a equilateral triangle.④Common grounding system is adopted. use the steel structure in tower foundation for natural earthing electrode, and the measures to reduce earthing resistance is taken.⑤The power system should be equipped with four levels power surge protection device(SPD).⑥Other comprehensive measures including down-conductor system, equipotential bonding, shielding, and surge protection device(SPD) on signal system should be adopted to protect the radar station from lightning.