用于高频脉冲电压下变频电机绝缘放电检测的特高频天线设计  

Design of Ultra-high Frequency Antenna for Discharge Detection Under High Frequency Impulsive Voltage Conditions for Inverter-fed Motors Insulation

作　　者：马世金 王鹏[1] 董涵 顾洋豪 周婉亚 MA Shijin;WANG Peng;DONG Han;GU Yanghao;ZHOU Wanya(College of Electrical Engineering,Sichuan University,Chengdu 610065,China;Southwest Electric Power Design Institute,Chengdu 610021,China)

机构地区：[1]四川大学电气工程学院,成都610065 [2]西南电力设计院有限公司,成都610021

出　　处：《高电压技术》2020年第10期3451-3459,共9页High Voltage Engineering

基　　金：国家自然科学基金(51977134)。

摘　　要：由于电力电子器件高频开断产生的强电磁干扰,正弦电压下测试技术已不适用于陡脉冲电压下变频电机绝缘局部放电检测。对此,通过在传统阿基米德平面螺旋天线上添加微带巴伦实现阻抗匹配,并在天线辐射面上覆盖高介电常数介质优化天线结构,提升了天线在0.5~1.5GHz频带的增益性能,增加了重复脉冲下放电检测高频信噪比,从而解决了纳秒陡脉冲强电磁干扰下局部放电检测技术难题。然后,利用所设计的脉冲电压下特高频传感器,实验研究了重复脉冲参数和传感器布置对变频电机绝缘放电时频信号影响规律。研究表明,重复脉冲电压下放电信号能量在0.5~1.3GHz范围内随天线放置距离增加非线性衰减;在高频区域重复脉冲频率对放电频谱影响显著,放电特高频信号随频率增加衰减严重。结合传感器建模仿真、实物制作和实验验证,得出高频脉冲下用于变频电机绝缘放电检测的最佳阿基米德平面螺旋天线参数和布置方式:当介质覆层厚度为1mm,距天线辐射面的距离d=30 mm时,在500~900 MHz频带范围内增益均大于2.5 dB,在900 MHz^2.0 GHz频带范围内增益大于7.0 dB,且驻波比小于1.4。研究结论为高频脉冲电压下特高频放电检测提供实验基础和参考。Due to the electromagnetic interference produced by the high frequency switching on/off of power electronic devices,the detection technology under sinusoidal condition cannot be used for the detection of partial discharge(PD)under impulsive voltages with fast rise times.In this paper,a microstrip Balun is added to realize impedance matching and a dielectric layer with high permittivity is loaded on the radiation surface of the antenna to optimize the antenna structure.The gain of the antenna is improved in high frequency bandwidth of 0.5~1.5 GHz and the signal-to-noise ratio is enhanced distinctly.Then,we studied the time-frequency statistical characteristics of PD under different square pulse voltage parameters and antenna placement distance by using the UHF antenna designed for PD detection under voltage with fast rise time.Experimental results show that the amplitude of UHF signal in the frequency domain of 0.5~1.3 GHz decreases non-linearly with the increase of antenna placement distance.The influence of voltage frequency on the high frequency components of the discharge is remarkable,and the PD signal decays seriously with the increase of frequency.Through the simulation and experimental verification of the antenna,the optimal parameters are obtained.The thicknesses of the dielectric cover is 1 mm,and the distance from the radiation surface of the antenna is d=30 mm.The gain is greater than 2.5 dB in the 500~900 MHz frequency band,greater than 7.0 dB in the 900 MHz^2 GHz frequency band,and the standing wave ratio is less than 1.4.The results obtained in this study can provide references and theoretical supports for PD detection of inverter-fed motor under high-frequency pulse voltage.

关 键 词：变频电机 绝缘系统 局部放电 重复方波脉冲电压 阿基米德螺旋天线 介质覆盖层 

分 类 号：TM855[电气工程—高电压与绝缘技术]