射频识别技术(Radio Frequency Identification,RFID)是通过发射和接收射频信号的方式来对目标对象进行识别,并由此获取目标对象的相关参数的技术。随着UHF RFID技术被应用于越来越多的领域,为了能够更加快速地适应各种应用需求,论文将U...射频识别技术(Radio Frequency Identification,RFID)是通过发射和接收射频信号的方式来对目标对象进行识别,并由此获取目标对象的相关参数的技术。随着UHF RFID技术被应用于越来越多的领域,为了能够更加快速地适应各种应用需求,论文将UHF RFID标签数字基带以SOC的形式实现。在整个数字基带设计中,标签的物理链路层通过硬件实现,包括FM0/Miller编码模块,PIE解码模块、CRC编码/校验模块等。同时,标签识别层通过使用开源RISC-V内核蜂鸟E203和部分硬件设计共同完成。经过验证,论文设计能够在FPGA上成功运行并符合ISO/IEC_18000-6C协议[1]中规定的通信流程。展开更多
特高频(ultra high frequency,UHF)局放检测是变压器油纸绝缘缺陷定位的常用方法,实际应用过程中局放定位准确性易受噪声和传感器布置方式影响。为保证变压器油纸绝缘缺陷局放定位检测有效性,文中首先建立油纸绝缘缺陷UHF局放定位检测平...特高频(ultra high frequency,UHF)局放检测是变压器油纸绝缘缺陷定位的常用方法,实际应用过程中局放定位准确性易受噪声和传感器布置方式影响。为保证变压器油纸绝缘缺陷局放定位检测有效性,文中首先建立油纸绝缘缺陷UHF局放定位检测平台,在常规K-means方法的基础上,提出基于修正聚类分界的变压器油纸绝缘缺陷局放抗干扰定位方法,有效降低了定位误差。然后针对样本聚类分界混叠问题,选择最优修正系数L为1.1时,UHF局放定位误差可减小至0.1 m内,验证了文中方法的有效性。最后分析不同传感器布置方式的定位误差变化规律,提出变压器油纸绝缘缺陷检测用UHF传感器优化布置方案,可为变压器局放在线监测传感器布置及定位提供参考。展开更多
Efforts to protect electric power systems from faults have commonly relied on the use of ultra-high frequency(UHF)antennas for detecting partial discharge(PD)as a common precursor to faults.However,the effectiveness o...Efforts to protect electric power systems from faults have commonly relied on the use of ultra-high frequency(UHF)antennas for detecting partial discharge(PD)as a common precursor to faults.However,the effectiveness of existing UHF antennas suffers from a number of challenges such as limited bandwidth,relatively large physical size,and low detection sensitivity.The present study addresses these issues by proposing a compact microstrip patch antenna with fixed dimensions of 100 mm×100 mm×1.6 mm.The results of computations yield an optimized antenna design consisting of 2nd-order Hilbert fractal units positioned within a four-layer serpentine arrangement with a fractal unit connection distance of 3.0 mm.Specifically,the optimized antenna design achieves a detection bandwidth for which the voltage standing wave ratio is less than 2 that is approximately 97.3%of the UHF frequency range(0.3–3 GHz).Finally,a prototype antenna is fabricated using standard printed circuit board technology,and the results of experiments demonstrate that the proposed antenna is capable of detecting PD signals at a distance of 8 m from the discharge source.展开更多
当采用特高频UHF(ultra high frequency)检测技术进行局部放电监测时,基本均假定GIS具有良好的同轴波导射频传播特性,并不能完全反应实际GIS运行情况。为了掌握实际复杂GIS形状下的UHF信号传播特性,文中设计“L”形测试截面以及现场实际...当采用特高频UHF(ultra high frequency)检测技术进行局部放电监测时,基本均假定GIS具有良好的同轴波导射频传播特性,并不能完全反应实际GIS运行情况。为了掌握实际复杂GIS形状下的UHF信号传播特性,文中设计“L”形测试截面以及现场实际GIS的“П”截面,并首先进行实验测试,分析“L”形截面对UHF信号传播特性的影响,但只能得到GIS绝缘间隙中局部位置(传感器位置)的信号强度;为此,文中建立了“L”形有限元模型FEM(finite element model),并将FEM分析结果与测试结果进行对比,证明了该有限元模型的正确性,以此为基础,可分析得到整个GIS绝缘间隙的UHF信号传播特性。结果表明,所提实验室“L”形截面测试结果和有限元模型能够真实反应实际情况,准确性高。展开更多
In view of the effective perception demand of PD(Partial Discharge)insulation defect of in-service GIS(Gas Insulated Switchgear),the external UHF(Ultra High Frequency,0.3−3 GHz)sensing technology for GIS PD insulation...In view of the effective perception demand of PD(Partial Discharge)insulation defect of in-service GIS(Gas Insulated Switchgear),the external UHF(Ultra High Frequency,0.3−3 GHz)sensing technology for GIS PD insulation defect fromresin hole is studied in this paper.Firstly,rectangular waveguide theory is used to analyze the electromagnetic wave propagation characteristics from rectangular resin hole in GIS disc insulator.It is found that the energy of leaked electromagnetic wave mainly concentrates in the frequency band above 1 GHz.Then based on this frequency band characteristics,a cavity-backed bowtie sensor for GIS PD external detection is designed optimized by HFSS finite element software,in band of 1–3 GHz,its maximum VSWR is 7,the minimum is 1.1,the average is 2.9,and in band of 0.3–1 GHz,the maximum and minimum VSWR is 42.8 and 7,the average is 20.6.Finally,a sensor prototype is made,its sensitivity experiment is carried out on 220 kV GIS,experimental results show that the designed sensor can stably detect the PD electromagnetic wave signal leaked fromthe resin hole,and the signal energy in frequency band range is consistent with the theoretical analysis results.展开更多
文摘射频识别技术(Radio Frequency Identification,RFID)是通过发射和接收射频信号的方式来对目标对象进行识别,并由此获取目标对象的相关参数的技术。随着UHF RFID技术被应用于越来越多的领域,为了能够更加快速地适应各种应用需求,论文将UHF RFID标签数字基带以SOC的形式实现。在整个数字基带设计中,标签的物理链路层通过硬件实现,包括FM0/Miller编码模块,PIE解码模块、CRC编码/校验模块等。同时,标签识别层通过使用开源RISC-V内核蜂鸟E203和部分硬件设计共同完成。经过验证,论文设计能够在FPGA上成功运行并符合ISO/IEC_18000-6C协议[1]中规定的通信流程。
文摘特高频(ultra high frequency,UHF)局放检测是变压器油纸绝缘缺陷定位的常用方法,实际应用过程中局放定位准确性易受噪声和传感器布置方式影响。为保证变压器油纸绝缘缺陷局放定位检测有效性,文中首先建立油纸绝缘缺陷UHF局放定位检测平台,在常规K-means方法的基础上,提出基于修正聚类分界的变压器油纸绝缘缺陷局放抗干扰定位方法,有效降低了定位误差。然后针对样本聚类分界混叠问题,选择最优修正系数L为1.1时,UHF局放定位误差可减小至0.1 m内,验证了文中方法的有效性。最后分析不同传感器布置方式的定位误差变化规律,提出变压器油纸绝缘缺陷检测用UHF传感器优化布置方案,可为变压器局放在线监测传感器布置及定位提供参考。
文摘Efforts to protect electric power systems from faults have commonly relied on the use of ultra-high frequency(UHF)antennas for detecting partial discharge(PD)as a common precursor to faults.However,the effectiveness of existing UHF antennas suffers from a number of challenges such as limited bandwidth,relatively large physical size,and low detection sensitivity.The present study addresses these issues by proposing a compact microstrip patch antenna with fixed dimensions of 100 mm×100 mm×1.6 mm.The results of computations yield an optimized antenna design consisting of 2nd-order Hilbert fractal units positioned within a four-layer serpentine arrangement with a fractal unit connection distance of 3.0 mm.Specifically,the optimized antenna design achieves a detection bandwidth for which the voltage standing wave ratio is less than 2 that is approximately 97.3%of the UHF frequency range(0.3–3 GHz).Finally,a prototype antenna is fabricated using standard printed circuit board technology,and the results of experiments demonstrate that the proposed antenna is capable of detecting PD signals at a distance of 8 m from the discharge source.
文摘当采用特高频UHF(ultra high frequency)检测技术进行局部放电监测时,基本均假定GIS具有良好的同轴波导射频传播特性,并不能完全反应实际GIS运行情况。为了掌握实际复杂GIS形状下的UHF信号传播特性,文中设计“L”形测试截面以及现场实际GIS的“П”截面,并首先进行实验测试,分析“L”形截面对UHF信号传播特性的影响,但只能得到GIS绝缘间隙中局部位置(传感器位置)的信号强度;为此,文中建立了“L”形有限元模型FEM(finite element model),并将FEM分析结果与测试结果进行对比,证明了该有限元模型的正确性,以此为基础,可分析得到整个GIS绝缘间隙的UHF信号传播特性。结果表明,所提实验室“L”形截面测试结果和有限元模型能够真实反应实际情况,准确性高。
基金supported by Science and Technology Project of SGCC(Research on Key Technologies for Fault Diagnosis and Early Warning of Intermittent Discharge in UHV GIS:524625200028).
文摘In view of the effective perception demand of PD(Partial Discharge)insulation defect of in-service GIS(Gas Insulated Switchgear),the external UHF(Ultra High Frequency,0.3−3 GHz)sensing technology for GIS PD insulation defect fromresin hole is studied in this paper.Firstly,rectangular waveguide theory is used to analyze the electromagnetic wave propagation characteristics from rectangular resin hole in GIS disc insulator.It is found that the energy of leaked electromagnetic wave mainly concentrates in the frequency band above 1 GHz.Then based on this frequency band characteristics,a cavity-backed bowtie sensor for GIS PD external detection is designed optimized by HFSS finite element software,in band of 1–3 GHz,its maximum VSWR is 7,the minimum is 1.1,the average is 2.9,and in band of 0.3–1 GHz,the maximum and minimum VSWR is 42.8 and 7,the average is 20.6.Finally,a sensor prototype is made,its sensitivity experiment is carried out on 220 kV GIS,experimental results show that the designed sensor can stably detect the PD electromagnetic wave signal leaked fromthe resin hole,and the signal energy in frequency band range is consistent with the theoretical analysis results.
