A new method of nuclear magnetic resonance for aging State detection of composite insulators

In order to measure the aging state of silicone rubber insulators, a new method of nuclear magnetic resonance(NMR) measurement is proposed and a portable low field NMR measurement system is developed. This paper introduced a design method of magnet and RF coil of NMR sensor and made a experiment about the aging of composite insulators on 220kV high voltage. The study draw a conclusion that the transverse relaxation time of composite insulators decreases with the increasing of running time. Therefore, low-field NMR can be used to evaluate the aging state of composite insulator umbrella skirt quantitatively.