中国电机工程学报Issue(36)：6545-6553,9.DOI:10.13334/j.0258-8013.pcsee.2014.36.022
用于复合绝缘子伞裙老化无损检测的单边核磁共振方法
Non-destructive Aging Detection Method for Silicone Rubber Insulator Shed Based on Unilateral NMR Principle
摘要
Abstract
Silicone rubber insulator is widely used in the power system, the assessment and monitoring of its aging status are critical to the safe operation of the power system. This paper presented a non-destructive unilateral nuclear magnetic resonance(NMR) method to measure the aging status of silicon rubber insulator. The research included two parts: the design of the NMR sensor, and the analysis of the NMR signal. The magnet of the NMR sensor with a semi-elliptical structure was designed by finite element methods. A static magnetic field with constant gradient of 3.9T/m was built in the measurement area with a size of 10mm×10mm×4mm. With this gradient field, the detections of various depths into the insulator shed were realized. Three groups of insulators with different service times were measured, and the CPMG sequence was employed to excite the samples. By performing the Inverse Laplace transform to the peak-envelope curve of NMR echoes, the one dimensional distribution of transverse relaxation time was obtained. From the one dimensional distribution, the effective transverse relaxation timeT2ef was extracted. It demonstrates that:T2ef decreases as the service time of the insulator increases;T2ef decreases as the measurement moves from the middle part to the surface of the shed.T2ef can reflect the aging status of the silicone rubber insulator shed. The result can provide a new non-destructive detection method for assessing the aging level of the composite insulator.关键词
复合绝缘子/老化/单边核磁共振/无损检测/横向弛豫时间Key words
composite insulator/aging/unilateral nuclear magnetic resonance(NMR)/non-destructive detection/transverse relaxation time分类
信息技术与安全科学引用本文复制引用
徐征,程江艳,吴嘉敏,何为..用于复合绝缘子伞裙老化无损检测的单边核磁共振方法[J].中国电机工程学报,2014,(36):6545-6553,9.基金项目
国家自然科学基金项目(51107150、51377182)。Project Supported by National Natural Science Foundation of China(51107150,51377182) （51107150、51377182）
