基于VMD和改进双端行波法的电缆故障测距研究

Research on Cable Fault Location Based on VMD and Improved Dual Terminal Traveling Wave Method

针对传统电缆故障行波测距方法受波速、噪声、端点效应等影响导致定位误差大的问题,提出一种基于变分模态分解(variational mode decomposition,VMD)和改进双端行波法的故障测距方法。首先,提出改进的双端行波法消除波速对测距的影响;然后,在小波去噪基础上,利用VMD解决模态混叠和端点效应问题;最后,通过希尔伯特变换准确地标定故障波头。实例结果表明,基于VMD和改进双端行波法的电缆故障测距方法能有效降低波速、距离和过渡电阻对测距误差的影响,可准确地标定电缆故障位置。

To solve the large position error affected by wave velocity,noise,and end effects of the traditional cable fault location method based on traveling wave,this paper proposes a fault location method based on variational mode decomposition(VMD) and improved dual terminal traveling wave methods.At first,the improved dual terminal traveling wave method is proposed to eliminate the influence of wave velocity on distance measurement.Then,the VMD method is used to solve the problems of modal aliasing and endpoint effects on the basis of wavelet denoising.Finally,accurate calibration of the wave head for cable fault can be achieved by the Hilbert transform.Results indicate that the proposed cable fault location method based on the VMD and improved dual terminal methods can effectively mitigate the influence of wave velocity,distance,and transient resistance on the measurement error.Moreover,accurate calibration of cable fault location can be achieved.