测震台站综合防雷系统建设及效能评价

Construction and Evaluation of a Comprehensive Lightning Protection System for Seismic Stations

摘要:

介绍雷害对测震台站的危害方式,总结测震台站的综合防雷基本措施,包括地网改造、配电防雷、信号与通信防雷、布线规划与整理,创新地提出特定条件下安装退耦器以提高防雷效果。通过对比计算台基噪声与观测系统标定结果,研究综合防雷系统接入测震台站观测系统后对数据质量的影响,以进行防雷效能评价。

Abstract:

An analysis of the loss of seismic observation equipment in the Jiangsu Province of China since 2009 has revealed three primary reasons for equipment loss related to lightning strikes: (1) Unprotected digital seismic stations. (2) Data line interference from lightning, which is caused by excessive distances between sensors and data collectors. (3) The non-normalized installation of station lines. A summary of basic, yet comprehensive,lightning protection measures, combined with an analysis of actual event occurrences in the Jiangsu Province of China, are presented. These protective measures include: the reformation of the power grid, lightning protection for the distribution systems, lightning protection for signal and communications equipment, and the normalization of wiring plans. If seismic observation equipment and lightning protection equipment are to be connected in series, the background seismic noise and the calibration parameters must be checked. When selecting data for the calculation of background seismic noise, the following two points should be taken into consideration: (1) The data should be chosen from 00:00 to 01:00 every day, when the influence of human activity is minimized. (2) The data must contain no seismic event; otherwise, data should be chosen from the next hourly interval. Liyang Station is presented as a case study of the implementation of lightning protection system for a seismic station. Data from one month prior to the installation of the lightning protection system, one month during the operation of the lightning protection system, and one month during the following thunderstorm season are presented. This case study includes the calculation of the background seismic noise and the calibration parameters before and after the lightning protection system installation, and determines the actual influence of the lightning protection system on the quality of collected seismic data. An innovative installation scheme for decoupling devices, a first for the protection of seismic systems from lightning, is discussed.