An EXPERIMENTAL STUDY ON DIELECTRIC PARAMETERS OF XLPE INSULATED HIGH VOLTAGE CABLES UNDER DIFFERENT OPERATING CONDITIONS

Abstract

High voltage underground cables used in distribution systems provide benefits including aesthetics, reliability, low maintenance costs, and resistance to environmental factors. However, their initial installation expenses are considerably higher than overhead lines, and fault detection is quite challenging. Thus, a deep analysis of dielectric parameters is crucial. Typically, electrical specifications of high voltage underground cables provided by the manufacturer are used for nominal operating conditions. However, it is essential to acknowledge that variations in operational conditions have a discernible impact on the dielectric characteristics of cable insulation. This phenomenon results in an accelerated aging process of the insulation material and contributes to unexpected failures. Hence, it is imperative to determine dielectric parameters of cable insulation under varying operational conditions and elucidate the impact of these operational states on insulation properties. This study involved experimental determination of the dielectric parameters, including capacitance, relative dielectric constant, dielectric loss, and tanδ, for a XLPE insulated high voltage underground cable, designed for a nominal voltage of 12/20 kV. These assessments were performed under varying operating conditions, specifically for distinct voltage, temperature, and frequency. Based on the acquired findings, it is evident that the dielectric characteristics of the cable insulation exhibit substantial variations in response to alterations in voltage, temperature, and frequency, even when operating within the defined nominal limits.

Keywords

• High Voltage Cables
• Dielectric Loss
• Dielectric Loss Factor
• Energy Distribution

Supporting Institution

Yıldız Technical University, Scientific Research Projects Coordination Office

Project Number

2012-04-02-DOP01

Thanks

This study was supported by Yıldız Technical University, Scientific Research Projects Coordination Office, Project No: 2012-04-02-DOP01.

XLPE İZOLELİ YÜKSEK GERİLİM KABLOLARININ FARKLI İŞLETME KOŞULLARI ALTINDA DİELEKTRİK PARAMETRELERİ ÜZERİNE BİR ÇALIŞMA

Abstract

Dağıtım sistemlerinde kullanılan yüksek gerilim yer altı kabloları estetik, güvenilirlik, düşük bakım maliyetleri ve çevresel faktörlere dayanıklılık gibi avantajlar sağlar. Ancak bunların ilk kurulum maliyetleri, havai hatlara göre oldukça yüksektir ve arıza tespiti zordur. Bu nedenle dielektrik parametrelerinin derinlemesine analizi oldukça önemlidir. Yüksek gerilim yeraltı kablolarının üretici firma tarafından verilen elektriksel değerleri genellikle nominal işletme şartları için kullanılmaktadır. Ancak değişken işletme şartları, kablo yalıtımının dielektrik dielektrik parametrelerini de değiştirmekte olup yalıtımın daha hızlı yaşlanmasına ve beklenmeyen arızalara neden olmaktadır. Ancak değişken işletme şartlarında, kablo yalıtımının dielektrik parametreleri de değişmekte olup, sistemin çalışmasında aksamalara ve beklenmeyen arızalara neden olabilmektedir. Bu nedenle, kablo yalıtımının dielektrik parametrelerinin farklı işletme koşulları altında belirlenmesi ve bu işletme koşullarının yalıtım üzerindeki etkilerinin ortaya konması önem arz etmektedir. Bu çalışmada, 12/20 kV nominal gerilimli, XLPE izoleli bir yüksek gerilim yeraltı kablosunun, farklı işletme koşullarındaki (gerilim, sıcaklık ve frekans) dielektrik parametreleri (kapasite, bağıl dielektrik katsayısı, dielektrik kayıp, tanδ) deneysel olarak belirlenmiştir. Elde edilen sonuçlara göre, nominal çalışma sınırları içerisinde dahi kablo yalıtımının dielektrik özelliklerinin farklı gerilim, frekans ve sıcaklık ile önemli ölçüde değiştiği gözlemlenmiştir.

Keywords

• Yüksek Gerilim Kabloları
• Dielektrik Kayıp
• Dielektrik Kayıp Faktörü
• Enerji Dağıtımı

Project Number

2012-04-02-DOP01

References

1. Arikan, O., Uydur, C. C., & Kumru, C. F. (2023). Insulation evaluation of MV underground cable with partial discharge and dielectric dissipation factor measurements. Electric Power Systems Research, 220, 109338.
2. Arikan, O., Uydur, C. C., & Kumru, C. F. (2022). Prediction of dielectric parameters of an aged MV cable: A comparison of curve fitting, decision tree and artificial neural network methods. Electric Power Systems Research, 208, 107892.
3. Boggs, S., & Kuang, J. (1998). High field effects in solid dielectrics. Electrical Insulation Magazine, IEEE, 14(6), 5–12.
4. Bolivar, P. H., Brucherseifer, M., Rivas, J. G., Gonzalo, R., Ederra, I., Reynolds, A. L., Holker, M., & De Maagt, P. (2003). Measurement of the dielectric constant and loss tangent of high dielectric-constant materials at terahertz frequencies. IEEE Transactions on Microwave Theory and Techniques, 51(4 I), 1062–1066.
5. Chan, J. C., Hartley, M. D., & Hiivala, L. J. (1993). Performance characteristics of XLPE versus EPR as insulation for high voltage cables. IEEE Electrical Insulation Magazine, 9(3), 8–12.
6. Chmura, L., Jin, H., Cichecki, P., Smit, J. J., Gulski, E., & Vries, F. D. (2012). Use of dissipation factor for life consumption assessment and future life modeling of oil-filled high-voltage power cables. IEEE Electrical Insulation Magazine, 28(1), 27–37.
7. Cookson, A. H. (1990). Influence of electrical insulation on design and performance of power equipment. IEEE Electrical Insulation Magazine, 6(6), 7–10.
8. Ďurman, V., & Lelák, J. (2010). Influence of radiation on the dielectric properties of XLPE based insulation systems. Journal of Electrical Engineering, 61(4), 229–234.

9. Gockenbach, E., & Hauschild, W. (2000). The selection of the frequency range for high-voltage on-site testing of extruded insulation cable systems. IEEE Electrical Insulation Magazine, 16(6), 11–16.
10. Hampton, R. N. (2008). Some of the considerations for materials operating under high-voltage, direct-current stresses. IEEE Electrical Insulation Magazine, 24(1), 5–13.
11. Hernandez-mejia, J., Harley, R., Hampton, N., & Hartlein, R. (2009). Characterization of Ageing for MV Power Cables Using Low Frequency Tan δ Diagnostic Measurements. IEEE Transactions on Dielectrics and Electrical Insulation, 16(3), 862–870.
12. Hernandez-Mejia, J., Perkel, J., Harley, R., Hampton, N., & Hartlein, R. (2009). Correlation between tan δ diagnostic measurements and breakdown performance at VLF for MV XLPE cables. IEEE Transactions on Dielectrics and Electrical Insulation, 16(1), 162–170
13. International Electrotechnical Commission. (2014). IEC 60502-2: Power Cables with Extruded Insulation and Their Accessories for Rated Voltages from 1 kV (Um= 1.2 kV) up to 30 kV (Um= 36 kV), Part 2: Cables for Rated Voltages from 6 kV (Um= 7.2 kV) up to 30 kV (Um= 36 kV). International Electrotechnical Commission: Geneva, Switzerland.
14. Hvidsten, S., Holmgren, B., Adeen, L., & Wetterstrom, J. (2005). Condition assessment of 12-and 24-kV XLPE cables installed during the 80s. Results from a joint Norwegian/Swedish research project. IEEE Electrical Insulation Magazine, 21(6), 17-23.
15. Hou, Z., Shang, Y., Xu, Y., Du, M., Ju, Z., Teng, S., ... & He, W. (2023). On-site Insulation Tests for MV cable using Very Low Frequency and Damped AC Techniques. Advances in Engineering Technology Research, 4(1), 119-119.
16. Kalenderli, Ö., Arıkan, O., & Kocatepe, C. (2005). Çözümlü Problemlerle Yüksek Gerilim Tekniği. Birsen.
17. Kaplan, O., Yavanoglu, U., & Issi, F. (2012). Country study on renewable energy sources in Turkey. 2012 International Conference on Renewable Energy Research and Applications (ICRERA), 1–5.
18. Lelak, J., Durman, V., Packa, J., & Olach, O. (2002, April). Diagnostics of medium voltage PVC cables by dissipation factor measurement at very low frequency. IEEE International Symposium on Electrical Insulation, 79-82.
19. Liu, T., Fothergill, J., Dodd, S., & Nilsson, U. (2009). Influence of semicon shields on the dielectric loss of XLPE cables. 2009 IEEE Conference on Electrical Insulation and Dielectric Phenomena, 246–249.
20. Mahalik, N. P. (1997, May). A digital meter for measuring dissipation factor. 5th International Conference on Properties and Applications of Dielectric Materials, 1129-1131.
21. Malpure, B. D., & Baburao, K. (2008). Failure analysis & diagnostics of power transformer using dielectric dissipation factor. Proceedings of 2008 International Conference on Condition Monitoring and Diagnosis, CMD 2008, 497–501.
22. Mazzanti, G., Montanari, G. C., & Simoni, L. (1997). Insulation characterization in multistress conditions by accelerated life tests: An application to XLPE and EPR for high voltage cables. IEEE Electrical Insulation Magazine, 13, 24–34.
23. Morsalin, S., & Phung, B. T. (2019). Modeling of dielectric dissipation factor measurement for XLPE cable based on Davidson-Cole model. IEEE Transactions on Dielectrics and Electrical Insulation, 26(3), 1018-1026.
24. Oyegoke, B., Hyvonen, P., Aro, M., & Ning, G. (2003). Application of dielectric response measurement on power cable systems. Dielectrics and Electrical Insulation, IEEE Transactions On, 10(5), 862–873.
25. Pascoli, G., Hribernik, W., & Újvári, G. (2008). A practical investigation on the correlation between aging and the dissipation factor value of mica insulated generator windings. 2008–2011.
26. Peng, D., Yang, D., Wang, C., & Li, M. (2009). The influence of transformer oil aging to dielectric dissipation factor and its insulating lifetime. Asia-Pacific Power and Energy Engineering Conference, APPEEC, 1–4.
27. Ponniran, A., & Kamarudin, M. S. (2008). Study on the performance of underground XLPE cables in service based on tan delta and capacitance measurements. PECon 2008 - 2008 IEEE 2nd International Power and Energy Conference, PECon 08, 39–43.
28. Song, H., Gao, L., Wang, Y., & Wu, B. (2007). Development of Digital Measuring Instrument for Dielectric Loss Tangent. 8th International Conference on Electronic Measurement and Instruments, 2007. ICEMI ’07., 1–106.
29. Suwarno, S., & Salim, F. S. F. (2006). Effects of Electric Arc on The Dielectric Properties of Liquid Dielectrics. 2006 IEEE 8th International Conference on Properties & Applications of Dielectric Materials, tan 6, 482–485.
30. Vahedy, V. (2006). Polymer insulated high voltage cables. IEEE Electrical Insulation Magazine, 22(3), 13–18.
31. Wang, P., Raghuveer, M. R., McDermid, W., & Bromley, J. C. (2001). A digital technique for the on-line measurement of dissipation factor and capacitance. IEEE Transactions on Dielectrics and Electrical Insulation, 8(2), 228–232.
32. Werelius, P., Ohlen, M., & Robalino, D. M. (2012). Dielectric frequency response measurements and dissipation factor temperature dependence. 2012 IEEE International Symposium on Electrical Insulation, 296–300.
33. Zaengl, W. S. (2003a). Applications of dielectric spectroscopy in time and frequency domain for HV power equipment. IEEE Electrical Insulation Magazine, 19(6), 9–22.
34. Zaengl, W. S. (2003b). Dielectric spectroscopy in time and frequency domain for HV power equipment. I. Theoretical considerations. IEEE Electrical Insulation Magazine, 19(5), 5–19.