管道平衡电磁内检测技术串联谐振激励电路研究

Research on Series Resonance Excitation Circuit of Pipeline Balance Electromagnetic Internal Detection Technology

针对平衡电磁技术对管道内表面周向、轴向裂纹缺陷检测的灵敏度问题,提出采用串联谐振激励电路增大激励电流,提升检测灵敏度的方法。利用电磁场理论分析了平衡电磁技术激励电流对检测信号的影响,以有限元仿真的方式计算了不同激励电流下检测信号的曲线与幅值,研究了串联谐振电路减小激励线圈阻抗,增加激励电流的机理,设计了基于串联谐振的激励电路,通过检测实验验证了串联谐振激励电路对检测灵敏度的作用,结果表明,串联谐振电路可以使管道表面周向裂纹检测灵敏度提升317.8%,轴向裂纹检测灵敏度提升307.7%。

Aiming at the sensitivity of the balanced electromagnetic technology to the detection of circumferential and axial crack defects on the inner surface of the pipeline,a method using a series resonance excitation circuit to increase the excitation current and improve the detection sensitivity was proposed.The electromagnetic field theory was used to analyze the influence of the excitation current of the balanced electromagnetic technology on the detection signal.The curve and amplitude of the detection signal under different excitation currents were calculated by means of finite element simulation.The series resonance circuit was studied to reduce the excitation coil impedance and increase the excitation current.An excitation circuit based on series resonance was designed,and the effect of the series resonance excitation circuit on the detection sensitivity was verified through experiments.The results show that the use of a series resonance circuit can increase the detection sensitivity of pipe surface circumferential cracks by 317.8%,and axial cracks detection sensitivity is increased by 307.7%.