Electromagnetic ultrasonic SH guided wave detection method for grounded flat steel defects based on synchrosqueezed wavelet transforms
ZHOU Kai1, ZHANG Ruizhe1, YE Kuan1, LI Hongda1, WANG Zhe2, HUANG Songling2
1. State Grid Beijing Electric Power Research Institute, Beijing 100072, China; 2. State key Laboratory of Control and Simulation of Power System and Generation Equipments, Tsinghua University, Beijing 100084, China
Abstract：The grounding grid plays a vital role for ensuring reliable power system operations. However, the buried environment around the grounding grid can result in grounding device defects, so the grounding grid must be periodically tested. This paper presents a SH guided wave detection method based on linear frequency modulation excitation and synchrosqueezed wavelet transforms for grounded flat steel power systems. The system uses a permanent magnetic array SH guided wave transducer which is simple and suitable for flat steel structures. The transducer is excited with a linear frequency modulation signal with synchrosqueezed wavelet transforms used to analyze the signal. Identification of the overlapping guided wave signals in the time-frequency plane effectively distinguishes between various defects and end faces. Signals from finite element simulations and experiments were then used to evaluate the signal analysis method. The calculated distance errors were all within 3%, which shows that the method can accurately extract the guided wave travel times and accurately locate defects. Comparisons with results using short-time Fourier transforms and Wigner distributions show the advantages of the time-frequency aggregation of the synchrosqueezed wavelet transforms.
[1] YANG H, LIU G Q, ZHANG L F, et al. Defect diagnosis methods and development trend for grounding grid[J]. Advanced Technology of Electrical Engineering and Energy, 2016, 35(10): 35-42. (in Chinese) 杨虹, 刘国强, 张来福, 等. 电力系统接地网缺陷诊断方法及发展趋势[J]. 电工电能新技术, 2016, 35(10): 35-42. [2] WANG S, ZHANG B, ZHANG J, et al. Measurement method of impulse grounding impedance of grounding device[J]. Power System Technology, 2019, 43(1): 356-362. (in Chinese) 王森, 张波, 张健, 等. 接地装置冲击接地电阻测试方法[J]. 电网技术, 2019, 43(1): 356-362. [3] XU Y Q, YANG H, LI P. Earth fault analysis on low resistance grounded distribution network with inverter interfaced distribution generation[J]. Electrical Measurement & Instrumentation, 2018, 55(16): 57-63, 71. (in Chinese) 徐玉琴, 杨浩, 李鹏. 含逆变型分布式电源的小电阻接地方式配电网单相接地故障分析[J]. 电测与仪表, 2018, 55(16): 57-63, 71. [4] CHEN J W, QIAN Z H, ZHU L W, et al. Application of electrochemical noise to soil corrosion monitoring of grounding grid[J]. Corrosion & Protection, 2016, 37(5): 371-374. (in Chinese) 陈建伟, 钱洲亥, 祝郦伟, 等. 电化学噪声在接地网土壤腐蚀监控中的应用[J]. 腐蚀与防护, 2016, 37(5): 371-374. [5] MA G, JIANG L R, XU G C. Study on corrosion fault diagnosis for grounding grid based on the Tellegen's Theorem[J]. Electrical Measurement & Instrumentation, 2016, 53(22): 91-95. (in Chinese) 马刚, 蒋林洳, 徐谷超. 基于特勒根定理的接地网腐蚀诊断研究[J]. 电测与仪表, 2016, 53(22): 91-95. [6] ZHONG Q. Research on non-destructive testing of grounding grids in substations using ultrasonic guided waves[D]. Beijing: Beijing University of Technology, 2012. (in Chinese) 钟茜. 电力系统扁钢超声导波无损评价方法研究[D]. 北京: 北京工业大学, 2012. [7] SHI H, WANG F H, HU X M, et al. Experimental studies on substation grounding grid fault diagnosis using electromagnetic diagnosis method[J]. Electrical Measurement & Instrumentation, 2018, 55(16): 6-12. (in Chinese) 施会, 王丰华, 胡徐铭, 等. 变电站接地网电磁诊断法的试验研究[J]. 电测与仪表, 2018, 55(16): 6-12. [8] KOU X K, ZHANG K, ZHANG S Y, et al. Study on grounding grid connective resistance of large-scale substation[J]. Power System Technology, 2008, 32(2): 88-92. (in Chinese) 寇晓, 张科, 张嵩阳, 等. 大型变电站接地网导通状况研究[J]. 电网技术, 2008, 32(2): 88-92. [9] ZENG L, LUO Z, LIN J, et al. Excitation of Lamb waves over a large frequency-thickness product range for corrosion detection[J]. Smart Materials and Structures, 2017, 26(9): 095012. [10] WANG Z, HUANG S L, WANG S, et al. Compressed sensing method for health monitoring of pipelines based on guided wave inspection[J]. IEEE Transactions on Instrumentation and Measurement, 2020, 69(7): 4722-4731. [11] SEN D, AGHAZADEH A, MOUSAVI A, et al. Data-driven semi-supervised and supervised learning algorithms for health monitoring of pipes[J]. Mechanical Systems and Signal Processing, 2019, 131: 524-537. [12] HUANG S L, WANG Z, WANG S, et al. Review on advances of pipe electromagnetic ultrasonic guided waves technology and its application[J]. Chinese Journal of Scientific Instrument, 2018, 39(3): 1-12. (in Chinese) 黄松岭, 王哲, 王珅, 等. 管道电磁超声导波技术及其应用研究进展[J]. 仪器仪表学报, 2018, 39(3): 1-12. [13] RIBICHINI R, CEGLA F, NAGY P B, et al. Study and comparison of different EMAT configurations for SH wave inspection[J]. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2011, 58(12): 2571-2581. [14] ZHANG C, LIU S Z, YANG Q X, et al. Experiment of crack detection of metal plate based on electromagnetically induced acoustic emission[J]. Advanced Technology of Electrical Engineering and Energy, 2011, 30(1): 84-88. (in Chinese) 张闯, 刘素贞, 杨庆新, 等. 基于电磁声发射的金属板裂纹检测实验研究[J]. 电工电能新技术, 2011, 30(1): 84-88. [15] WANG Z, HUANG S L, WANG S, et al. Multifrequency identification and exploitation in lamb wave inspection[J]. IEEE Access, 2019, 7: 150435-150443. [16] LEE J S, KIM Y Y, CHO S H. Beam-focused shear-horizontal wave generation in a plate by a circular magnetostrictive patch transducer employing a planar solenoid array[J]. Smart Materials and Structures, 2008, 18(1): 015009. [17] ARUN K, DHAYALAN R, BALASUBRAMANIAM K, et al. An EMAT-based shear horizontal (SH) wave technique for adhesive bond inspection[J]. AIP Conference Proceedings, 2012, 1430(1): 1268-1275. [18] WU J J, TANG Z F, YANG K J, et al. Signal strength enhancement of magnetostrictive patch transducers for guided wave inspection by magnetic circuit optimization[J]. Applied Sciences, 2019, 9(7): 1477. [19] SEUNG H M, PARK C I, KIM Y Y. An omnidirectional shear-horizontal guided wave EMAT for a metallic plate[J]. Ultrasonics, 2016, 69: 58-66. [20] SEUNG H M, KIM Y Y. Generation of omni-directional shear-horizontal waves in a ferromagnetic plate by a magnetostrictive patch transducer[J]. NDT & E International, 2016, 80: 6-14. [21] WANG Z, HUANG S L, WANG S, et al. A damage localization method with multimodal lamb wave based on adaptive polynomial chirplet transform[J]. IEEE Transactions on Instrumentation and Measurement, 2020, 69(10): 8076-8087. [22] ZHU X J, HAN Z D, DU D, et al. Imaging and inspection of ultrasonic SH guided wave by synthetic aperture focusing[J]. Journal of Tsinghua University (Science and Technology), 2011, 51(5): 687-692. (in Chinese) 朱新杰, 韩赞东, 都东, 等. 基于合成孔径聚焦的超声SH导波成像检测[J]. 清华大学学报(自然科学版), 2011, 51(5): 687-692. [23] ZHANG Y, HUANG S L, ZHAO W, et al. Mode recognition of lamb wave testing signals of metal plate's defects based on STFT[J]. Electrical Measurement & Instrumentation, 2015, 52(4): 19-23. (in Chinese) 张宇, 黄松岭, 赵伟, 等. 基于STFT的金属板缺陷兰姆波检测信号模式识别[J]. 电测与仪表, 2015, 52(4): 19-23. [24] LI F C, MENG G. Dispersion analysis of Lamb waves with narrow frequency bands[J]. Acta Physica Sinica, 2008, 57(7): 4265-4272. (in Chinese) 李富才, 孟光. 窄频带Lamb波频散特性研究[J]. 物理学报, 2008, 57(7): 4265-4272. [25] ROSTAMI J, CHEN J M, TSE P W. A signal processing approach with a smooth empirical mode decomposition to reveal hidden trace of corrosion in highly contaminated guided wave signals for concrete-covered pipes[J]. Sensors, 2017, 17(2): 302. [26] WANG P, ZHOU W S, LI H. A singular value decomposition-based guided wave array signal processing approach for weak signals with low signal-to-noise ratios[J]. Mechanical Systems and Signal Processing, 2020, 141: 106450. [27] WANG Z, HUANG S L, WANG Q, et al. A new time-of-flight extraction method for narrowband Lamb wave in metallic plate[J]. The Applied Computational Electromagnetics Society Journal, 2019, 34(6): 985-990. [28] DAI D Y, HE Q B. Structure damage localization with ultrasonic guided waves based on a time-frequency method[J]. Signal Processing, 2014, 96: 21-28. [29] NURMALIA, NAKAMURA N, OGI H, et al. Mode conversion behavior of SH guided wave in a tapered plate[J]. NDT & E International, 2012, 45(1): 156-161. [30] WANG S, HUANG S L, WANG Q, et al. Mode identification of broadband Lamb wave signal with squeezed wavelet transform[J]. Applied Acoustics, 2017, 125: 91-101.
2022, Vol. 62 
