变压器缺陷发展过程中可见光与可闻声信号的特征规律及联合判据

电力变压器是电力系统中能量变换的重要设备,其故障会对电力系统供电可靠性和运行稳定性带来严重影响,因此对于变压器内部不同故障类型的判断就变得尤为重要。变压器发生故障时会产生明显的可闻声和可见光信号,研究不同放电形式下的信号特征,有助于变压器内部故障的准确判别。该文设计3种放电模型分别用于模拟变压器内极不均匀场放电、沿面放电和均匀场放电,测量并获得了各类缺陷下的可闻声和可见光信号,对比分析各信号间的差异和规律。研究发现:可闻声信号方面,极不均匀场放电主频为1980 Hz,沿面放电为200 Hz,均匀场放电为611 Hz;此外,沿面放电的可见光波长则集中在360~540 nm,极不均匀场和均匀场下的放电可见光能量均集中在482.8 nm和660.8 nm附近;单独通过可见光信号无法实现故障判别,但两类缺陷的可闻声信号主频特征并不同,两类信号结合起来可以更好地实现故障判别。研究结果可为变压器在线监测提供数据支撑和指导。

Large Stable Photoinduced Anisotropy and Optical Information Storage in Poly [4-bis (N, N-oxyethylene) imino-4- nitroasobenzene Succinyl] Film by Two-Wave Mixing

Optical information storage caused by photoinduced anisotropy in poly[4'-bis(N,N-oxyethylene)imino-4-nitroazobenzene succinyl]film is studied by two-wave mixing.Using Nd:YAG second-harmonic pulses(100ps),grating of orientation of azobenzene molecules is formed in the film by photoinduced anisotropy.Up to third-order diffraction was observed.After turning off one of the two pump lights,the signals remained.When the weaker one of two pump lights was turned off,the intensities of diffraction beams of another pump light almost did not decrease.The information recorded in the film can be 100%maintained for a long time(monitored over 100 days without obvious decrease).