Online calibration of high-frequency partial discharge signals in three-phase belted power cables

Partial discharge (PD) magnitudes from classical detection techniques are expressed in terms of apparent charges. Signals from HF/VHF/UHF techniques on substation components are often hard to express in this quantity because of complex signal excitation and propagation channels. A method to calibrate PD signals obtained during online inductive detection in medium voltage belted cables is described. online inductive detection implies that the impedances of components present in substations essentially determine the detected PD signal magnitude. The use of belted cables means, that the coupling of a PD event to the conductors not only depends on the PD site within the cross-section of the cable or cable accessory, but also becomes dependent on the momentary phase angle. In addition, during signal propagation the signal magnitude may alter according to the propagation modes of a multi-conductor cable. These aspects are studied quantitatively by the use of theoretical modelling in addition to offline and online experiments. PD diagnostic equipment including pulse injection capability allows online calibration with sufficient accuracy, irrespective of the actual substation arrangement.

[1]  P.A.A.F. Wouters,et al.  Challenges related to development of an on-line PD detection and localisation system , 2003 .

[2]  T. Sarkar,et al.  Analysis of Time Response of Lossy Multiconductor Transmission Line Networks , 1987 .

[3]  C. R. Paul,et al.  Decoupling the multiconductor transmission line equations , 1996 .

[4]  H. E. Orton.  Diagnostic testing of in-situ power cables: an overview , 2002, IEEE/PES Transmission and Distribution Conference and Exhibition.

[6]  P.A.A. Wouters,et al.  Effect of cable load impedance on coupling schemes for MV power line communication , 2003, 2003 IEEE Bologna Power Tech Conference Proceedings,.

[7]  J. Wetzer,et al.  Prebreakdown currents: Basic interpretation and time-resolved measurements , 1989 .

[8]  E. Gulski,et al.  PD measurements on-site using oscillating wave test system , 1998, Conference Record of the 1998 IEEE International Symposium on Electrical Insulation (Cat. No.98CH36239).

[9]  P.A.A.F. Wouters,et al.  Synchronization of on-line PD detection and localization setups using pulse injection , 2003, Proceedings of the 7th International Conference on Properties and Applications of Dielectric Materials (Cat. No.03CH37417).

[10]  M. S. Mashikian.  Partial discharge location as a diagnostic tool for power cables , 2000, 2000 IEEE Power Engineering Society Winter Meeting. Conference Proceedings (Cat. No.00CH37077).

[11]  P.A.A.F. Wouters,et al.  Sensors for on-line PD detection in MV power cables and their locations in substations , 2003, Proceedings of the 7th International Conference on Properties and Applications of Dielectric Materials (Cat. No.03CH37417).

[12]  J. Veen,et al.  The application of matched filters to PD detection and localization , 2003 .

[13]  E.F. Steenis,et al.  Partial discharge diagnostics of long and branched medium-voltage cables , 2001, ICSD'01. Proceedings of the 20001 IEEE 7th International Conference on Solid Dielectrics (Cat. No.01CH37117).

[14]  F. H. Kreuger,et al.  Partial Discharge Detection in High Voltage Equipment , 1990 .

[15]  T. Tanaka.  Partial discharge pulse distribution pattern analysis , 1995 .

[16]  P.A.A.F. Wouters,et al.  Fundamental aspects of excitation and propagation of on-line partial discharge signals in three-phase medium voltage cable systems , 2003 .