基于声光调制及RF相位检波的光纤干涉型局部放电超声传感方法研究  

Study on Fiber Interferometric Partial Discharge Ultrasonic Sensing Method Based on Acoustic-optic Modulation and RF Phase Detection

作　　者：邢超 乔辉 田源 赵军 高树国 史荣斌 马国明[2] XING Chao;QIAO Hui;TIAN Yuan;ZHAO Jun;GAO Shuguo;SHI Rongbin;MA Guoming(Electric Power Research Institute,State Grid Hebei Electric Power Co.,Ltd.,Shijiazhuang 050021,China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China)

机构地区：[1]国网河北省电力有限公司电力科学研究院,石家庄050021 [2]华北电力大学新能源电力系统国家重点实验室,北京102206

出　　处：《高压电器》2025年第3期152-159,共8页High Voltage Apparatus

基　　金：国网河北省电力有限公司科技项目(kj2021-215)。

摘　　要：变压器状态实时监测对于电力系统的安全稳定运行至关重要,通过检测变压器中局放信号以发现潜在绝缘缺陷,可大大提高电力系统中高压变压器的安全可靠性。文中针对局放超声信号光纤传感稳定性问题,开展光纤超声信号抗干扰及解调技术研究。分析环境噪声对传感系统稳定性的影响机制。为了提高系统稳定性,引入了声光调制器,将待测相位信息转移至高频载波,采用基于RF增益相位检波器的相位硬件解调方案。建立了光纤干涉超声传感系统,消除了传统干涉拓扑存在相位衰落问题对测量结果影响。最终,文中建立实验平台,实现基于光纤传感的局部放电声发射外置式传感。改进后光纤超声传感器,光纤超声传感器信噪比比传统PZT提升14.5 dB,在抗噪声干扰的同时,局部放电检测下限比PZT低21.83%,局部放电检测灵敏度比PZT高5.3倍,具有更低的检测下限和更高的超声信号检测的灵敏度。Real-time monitoring of transformer status is crucial to the safe and stable operation of power systems.Detection of partial discharge signal in transformers to find potential insulation defects can improve greatly the safety and reliability of high-voltage transformers in power systems.In view of the stability of optical fiber sensing of partial discharge ultrasonic signal in this paper,the study on anti-interference and modulation technology of the optical ultrasonic signal is developed.The influence mechanism of environmental noise on the stability of the sensing system is analyzed.For improving stability of the system,an acoustic-optic modulator is introduced to transfer the phase information to be measured to a high-frequency carrier,and a phase hardware demodulation scheme based on an RF gain-phase detector is adopted.A fiber optic interference ultrasonic sensing system is set up,which eliminates the influence of phase fading problem existing in traditional interference topology on the measurement result.Finally,an experimental platform is set up in this paper to realize the external sensing of partial discharge acoustic emission based on optical fiber sensing.The signal-to-noise ratio of the improved optical fiber ultrasonic sensor is 14.5 dB higher than that of traditional PZT.At the same time of noise and interference resistance,the lower limit of partial discharge detection is 21.83%lower than that of PZT,and the detection sensitivity of partial discharge is 5.3 times higher than that of PZT.It has lower detection lower limit and higher ultrasonic signal detection sensitivity.

关 键 词：局部放电 光纤超声传感 声光调制 RF相位检波 

分 类 号：TM855[电气工程—高电压与绝缘技术] TP212[自动化与计算机技术—检测技术与自动化装置]