Influence of Magnesium Oxide (MgO) Nanoparticles for High Voltage Direct Current (HVDC) Cable Insulation

Abstract:

This study discusses the development of enhanced insulating materials for High Voltage Direct Current (HVDC) cable insulations by reinforcing Low-Density Polyethylene (LDPE) with nanomagnesia (MgO) particles. The main emphasis of this work is to investigate the DC breakdown voltage performance of LDPE/MgO nanocomposites as a function of filler content. Increase in DC breakdown strength is very important for long-term reliability and safety of HVDC cable insulation. Besides electrical performance, tensile strength and morphological study were made as complementary studies to check the mechanical stability and quality of particle dispersion. The nanocomposites were fabricated using the melt-blending method, where 40 grams of LDPE was mixed with 1.25 wt.%, 2.5 wt.% and 5wt.% of nanomagnesia at 170 [°C] and 50 rpm (rotation per minute) using a Haake internal mixer. The resulting materials were hot-pressed into 1 mm thin films at 160 [°C] and 50 bar pressure. DC breakdown voltage tests were conducted on the samples to determine their breakdown voltage. Tensile testing was conducted for the mechanical property evaluation where the LDPE and 2.5 wt% MgO composite show slightly lower strain, indicating decreased ductility. Overall, the incorporation of MgO enhances stiffness but reduces flexibility and strain-hardening capacity, resulting in a stronger yet less ductile material. Scanning Electron Microscopy (SEM) was undertaken to complement the results, which included the dispersion quality of MgO particles and the filler interfacial bonding. Results indicated that nanomagnesia incorporation improved the DC breakdown voltage of LDPE, with the optimum value at 2.5 wt.% of MgO. At this loading, the material showed the strongest dielectric strength while retaining reasonable tensile properties. Thus, this study has proven that LDPE reinforced with 2.5 wt.% of nanomagnesia is a viable and efficient insulation material for HVDC cable applications at average of 40.1 [kV] compared to pure LDPE at 32.41 [kV].

• Periodical: Materials Science Forum (Volume 1189)
• Pages: 73-81
• DOI: https://doi.org/10.4028/p-9UwhAv
• Online since: May 2026
• Authors: Z.K. Hong, Noor Fadzilah Mohamed Sharif*, Norshafarina Ismail, M.N. Nazatul Shiema, Nor Laili Ismail
• Keywords: High Voltage Cable, High Voltage Direct Current (HVDC), High Voltage Insulator, LDPE, MgO, PE

References

[1] Information on https://hdl.handle.net/10419/96759

[2] D.A Woodford, HVDC transmission, Manitoba HVDC Research Centre, 18. 1998.

[3] K. Meah, and S. Ula, Comparative evaluation of HVDC and HVAC transmission systems, IEEE Power Engineering Society General Meeting (2007) 1-5.

DOI: 10.1109/pes.2007.385993

[4] Y. Zhou, S. Peng, J. Hu, and J. He, Polymeric insulation materials for HVDC cables: Development, challenges and future perspective, IEEE Transactions on Dielectrics and Electrical Insulation, vol. 24, no. 3, (2017), 1308–1318.

DOI: 10.1109/tdei.2017.006205

[5] T. Maezawa, T. Kishi, Y. Tanaka, Y. Takada, et al., Dependence of Filler Size on Space Charge Formation in LDPE/MgO under High Electric Field at High Temperature, 2008 International Symposium on Electrical Insulating Materials (ISEIM 2008). IEEE, (2008), 139-142.

DOI: 10.1109/iseim.2008.4664516

[6] G. Mazzanti, Issues and challenges for hvdc extruded cable systems, Aug. 01, 2021, Energies 14.15 (2021): 4504.

DOI: 10.3390/en14154504

[7] Y. Juanjuan. Study on electrical characteristics of XLPE insulation of high voltage cable. Diss. (2009).

[8] T. Kikuma, N. Fuse, T. Tanaka, Y.Murata and Ohki, Y., Filler-content dependence of dielectric properties of low-density polyethylene/MgO nanocomposites, IEEJ Transactions on Fundamentals and Materials, 126(11), (2006). 1072-1077.

DOI: 10.1541/ieejfms.126.1072

[9] N. Bowler, 2018 IEEE Conference on Electrical Insulation and Dielectric Phenomena, 2018 [Bulletin Board], IEEE Electrical Insulation Magazine, 35(1), (2018), 68-69.

DOI: 10.1109/mei.2019.8575691

[10] D. Xie, D. Min, Y. Huang, S. Li, M. T. Nazir, and B. T. Phung, Classified effects of nanofillers on DC breakdown and partial discharge resistance of polypropylene/alumina nanocomposites, IEEE Transactions on Dielectrics and Electrical Insulation, (2019) 698–705.

DOI: 10.1109/tdei.2018.007610

[11] Y. Murakami, M. Nemoto, S. Okuzumi, et al., DC Conduction and Electrical Breakdown of MgO/LDPE Nanocomposite, IEEE Transactions on Dielectrics and Electrical Insulation, (2008) 15(1), 33.

DOI: 10.1109/t-dei.2008.4446734

[12] C. Wang, J. Wang, C. Wu, W. Li, Z. Yang, and K. Wu, Study on Thermal Conductivity of BNNs/Mg (OH)/LDPE Composites Based on Melt Blending Method, in Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials, Institute of Electrical and Electronics Engineers Inc., (2021). 214–217.

DOI: 10.1109/icpadm49635.2021.9493996

[13] L. Zhang, H. Xu, and W. Wang, Performance of straw/linear low density polyethylene composite prepared with film-roll hot pressing, Polymers (Basel), (2020) vol. 12, no. 4.

DOI: 10.3390/polym12040860

[14] T. Y. Qiu, M. Song, and L. G. Zhao, "Testing, characterization and modelling of mechanical behaviour of poly (lactic acid) and poly (butylene succinate) blends," Mechanics of Advanced Materials and Modern Processes, (2016) 2(1).

DOI: 10.1186/s40759-016-0014-9

[15] C. Zhang, T. Mori, T. Mizutani, and J. Polychem, Effects of Manufacturing: Technolon on Electrical Breakdown and Morpholoiof Thin Flms of Low-Density Polyethylene Blended with Polypropylene Copolymer and MitSUgU lshioka, (2003).

DOI: 10.1109/tdei.2003.1207469

[16] J. Zhang, J. Li, Y. Wang, L. Bao, and X. Zhang, Electrical Breakdown Properties of Low-Density Polyethylene under DC Voltage, 2014 ICHVE International Conference on High Voltage Engineering and Application (2014), 1-4.

DOI: 10.1109/ichve.2014.7035400

[17] M. S. Khalil, The role of BaTiO/sub-3/in modifying the dc breakdown strength of LDPE, IEEE Transactions on Dielectrics and Electrical Insulation, 7(2), (2000) 261-268.

DOI: 10.1109/94.841819

[18] W. Elhrari, The Influence of LDPE Content on the Mechanical Properties of HDPE/LDPE Blends, Research & Development in Material Science, vol. 7, (2018) 5.

DOI: 10.31031/rdms.2018.07.000672