基于EFPI膜片纳米级振幅识别的电晕放电检测

Corona Discharge Detection Based on Extrinsic Fabry-Perot Interferometric Diaphragm Na-noscale Amplitude Recognition

为检测微弱局部放电,评估局部放电严重程度,提出了基于声敏感膜片纳米级振幅解调的光纤非本征型法布里-珀罗(extrinsic Fabry-Perot interferometric,EFPI)超声传感器电晕放电检测的新方法。首先,结合理论分析,设计制作了共振频率为55.5 kHz的EFPI探头。然后,研究了可解调纳米级膜片振幅的相位生成载波-反正切算法。基于EFPI探头和相位生成载波-反正切算法搭建EFPI超声传感器,并采用单点声源与点火脉冲发生器对传感器进行标定。EFPI超声传感器对膜片振幅的分辨率不低于0.43 nm,具有良好的响应线性度与超声信号检测能力。最后,将EFPI探头内置于电晕放电试验装置,实现13.86 pC局放量的检测。同时,结合Bootstrap小样本分析法建立膜片振幅与电晕放电发展情况的联系。试验结果表明:膜片振幅大小随放电电压呈指数增长,与局放量随电压变化的趋势相似,即膜片振幅大小与电晕放电严重程度相关。

To detect weak partial discharges and evaluate the severity of partial discharge,a novel corona discharge de-tection method based on acoustic-sensitive diaphragm nanoscale amplitude demodulation for an optical fiber extrinsic Fabry-Perot(EFPI)ultrasonic sensor was proposed.Firstly,an EFPI probe with a resonance frequency of 55.5 kHz was designed based on theoretical analysis.Then,the phase generated carrier arc-tangent algorithm(PGC-Atan)was investigated to demodulate the weak amplitude of the diaphragm.The EFPI ultrasonic sensor was constructed based on the EFPI and PGC-Atan algorithm,and its performances were verified by a single-point sound source and ignition pulse generator.The resolution of the EFPI ultrasonic sensor to the amplitude of the diaphragm can reach 0.43 nm,and it has good linearity of response and ultrasonic signal detection ability.Finally,the EFPI was installed into the experimental device to detect the air corona discharge,and 13.86 pC partial discharge magnitude was achieved.The relationship between the diaphragm amplitude and the corona discharge development was established by Bootstrap small sample analysis.The experimental results indicate that the amplitude of the diaphragm increases exponentially with the discharge voltage,which is similar to the variation trend of the partial discharge magnitude with the voltage.The amplitude of the diaphragm is related to the severity of corona discharge.