Characteristics of partial discharge pulses propagation in shielded power cable

Abstract Partial discharges originates from defects in the insulation material of shielded power cable, joints and machine coil. In cable the discharges induce small high frequency pulses which propagate to both cable ends and the time domain reflectometry detection method of the PD pulse is suitable in this case. In this paper, a new experimental method has been introduced, it consist to inject at one end of the power cable one high frequency pulse generated by negative corona discharge in point-plane system. Understanding high-frequency attenuation in transmission cable is relevant for PDs detection and wideband signals distributions over such cable. We have realized in laboratory a high frequency pulse generator and 50 m length of 30 kV XLPE power cable is used for the tests. The experimental results show that the pulse amplitude decreases and the pulse width increases with the propagated distance and this result is in good agreement with the actual theoretical analysis based on the frequency attenuation. Important characteristics of PD pulse are successively determined at high frequency with maximum accuracy possible such as the wave speed, the relative permittivity, the characteristic impedance and the XLPE attenuation factor.

[1]  S. Boggs,et al.  High frequency properties of shielded power cable - part 1: overview of mechanisms , 2005, IEEE Electrical Insulation Magazine.

[2]  R. Eriksson,et al.  Measurement technique for high frequency characterization of semiconducting materials in extruded cables , 2004, IEEE Transactions on Dielectrics and Electrical Insulation.

[3]  Xiuchen Jiang,et al.  Propagation Characteristics of Partial Discharge Signals , 2010 .

[4]  N. Oussalah,et al.  Analytic Solutions for Pulse Propagation in Shielded Power Cable for Symmetric and Asymmetric PD Pulses , 2007, IEEE Transactions on Dielectrics and Electrical Insulation.

[5]  Per Wiklund,et al.  Copper Dissolution and Metal Passivators in Insulating Oil , 2007, IEEE Electrical Insulation Magazine.

[6]  G. W. Trichel.  The Mechanism of the Negative Point to Plane Corona Near Onset , 1938 .

[7]  Chunchuan Xu,et al.  High frequency properties of shielded power cable. 3. Loss from neutral wire-shield interaction , 2007, IEEE Electrical Insulation Magazine.

[8]  Y. Zebboudj,et al.  Positive corona inception in HVDC configurations under variable air density and humidity conditions , 2000 .

[9]  H. Edin,et al.  Couplers for on-line time domain reflectometry diagnostics of power cables , 2004, The 17th Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2004. LEOS 2004..

[10]  M. Vakilian,et al.  Investigation of high frequency signal propagation characteristics on HV XLPE cables , 2005, 2005 International Power Engineering Conference.

[11]  Steven A. Boggs,et al.  Partial discharge. XXII. High frequency attenuation in shielded solid dielectric power cable and implications thereof for PD location , 1996 .

[12]  S.A. Boggs,et al.  High frequency properties of shielded power cable. Part 2: sources of error in measuring shield dielectric properties , 2006, IEEE Electrical Insulation Magazine.

[13]  S.A. Boggs,et al.  Partial Discharge Pulse Propagation in Shielded Power Cable and Implications for Detection Sensitivity , 2007, IEEE Electrical Insulation Magazine.