金属板缺陷负电晕检测中Trichel脉冲特性研究

Trichel Pulse Characteristics in Negative Corona Testing of Metal Plate Defects

现有的金属板缺陷无损检测技术已趋于成熟,并且可以实现对缺陷的检出、量化甚至三维成像。但是传统无损检测方法的缺陷检测灵敏度受到诸多外在条件以及算法复杂度等的限制,难以实现对微小缺陷的检测。因此,作为负电晕放电检测方法在无损检测领域的首次尝试,该文提出一种基于负电晕放电Trichel脉冲的金属板缺陷非接触式检测技术。该方法利用空间中带电粒子行为对电极结构敏感的特性,将Trichel脉冲电流波形参数作为负电晕放电现象的外在特征,对缺陷是否存在及严重程度进行初步判断。此外,建立电晕检测几何模型与仿真模型,并搭建针–板放电实验平台对仿真结果进行验证。研究结果表明,通过分析负电晕放电所特有的Trichel脉冲波形参数,可以对待测金属板存在缺陷与否进行有效地识别,在缺陷高灵敏度检测及后续的缺陷轮廓重构中具有一定的应用潜力。

Relevant research on non-destructive testing technology for metal plate defects is very comprehensive,and it can achieve the detection,quantification and 3D imaging of defects.However,the defect detection sensitivity of traditional non-destructive testing method is limited by many conditions and the complexity of the algorithm,making it difficult to detect small defects.Therefore,as the first attempt of the negative corona discharge method in the field of nondestructive testing,this paper innovatively proposes a metal plate defect detection method based on the Trichel pulse in negative corona discharge.The charged particles are sensitive to the electrode structure,which are used to make a preliminary judgment on the existence and severity of defects by analyzing the Trichel pulse current as the external characteristic of the negative corona discharge phenomenon.Moreover,the corona detection geometric and simulation models are established,and a needle-to-plane discharge experiment platform is built to verify the simulation results.Results show that by analyzing the unique Trichel pulse waveform parameters,we can effectively identify whether the metal plate has defects or not.We believe that this method has certain application potential in the high-sensitivity defect detection.