Abstract
Low-density polyethylene (LDPE) has been widely used as an insulating material in high-voltage direct-current power cables. In this research, we investigate how to improve the electrical breakdown strength of LDPE by nanodoping method and the mechanism of improvement. MgO particles with an average diameter of 50 nm are mixed with LDPE to fabricate nanocomposites by using a toque rheometer. Five kinds of nanocomposite samples are fabricated with nanofiller loadings of 0.25 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt% and pure LDPE is made as the contrast. Then the nanocomposites are pressed into sheet samples about 100 μm by plate vulcanizing machine. The images observed by scanning electron microscope show nanoparticles are dispersed uniformly in LDPE matrix. X-ray diffraction is used to measure the bonding effect between nanoparticles and polymer matrix as well as the morphology of nanocomposites. The trap parameters such as trap levels are characterized by thermally stimulated depolarization current. The dc breakdown experiments indicate that the dc breakdown strength increases firstly and then decreases with an increase in nanofiller loading. The dc breakdown strength is enhanced by incorporating nano MgO and reaches the maximum value 377.06 kV/mm at around 0.5 wt%, which is 17.61% higher than the breakdown field of pure LDPE. The influences of bonding effect, morphology, and trap properties on dc electrical breakdown strength of LDPE nanocomposites are analyzed. It is found that incorporating a small amount of MgO nanoparticles into LDPE matrix enhance the bonding effect between nanoparticles and polymer matrix and establish isolated interfacial regions around nanoparticles. Then, deep traps are formed in the interfacial regions and molecular chains with occupied deep charges are difficult to move under electric force. Consequently, the dc electrical breakdown performance is improved. At higher nanofiller loadings, bonding effect is weakened and interfacial regions are overlapped so that carriers can migrate more easily and the dc electrical breakdown field is reduced.
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References
Jin, L., Du, B.X., Hang, X.: Suppressing interface charge between LDPE and EPDM for HVDC cable accessory insulation. IEEE Trans. Dielectr. Electr. Insul. 24(3), 1331–1339 (2017)
Liu, D., Hoang, A.T., Pourrahimi, A.M., Pallon, L.K.H., Nisson, F., Gubanski, S.M., Olsson, R.T., Hedenqvist, M.S., Gedde, U.W.: Influence of nanoparticle surface coating on electrical conductivity of LDPE/Al2O3 nanocomposites for HVDC cable insulations. IEEE Trans. Dielectr. Electr. Insul. 24(3), 1396–1404 (2017)
Lu, T., Feng, H., Zhao, Z., Cui, X.: Analysis of the electric field and ion current density under ultra high-voltage direct-current transmission lines based on finite element method. IEEE Trans. Magn. 43(4), 1221–1224 (2007)
Chahal, J.S., Reddy, C.C.: Space charge dynamics in LDPE. In: International Conference on Condition Assessment Techniques in Electrical Systems. Bangalore, India (2016)
Wang, S., Zha, J., Wu, Y., Ren, L., Dang, Z.: Preparation, microstructure and properties of polyethylene/alumina nanocomposites for HVDC insulation. IEEE Trans. Dielectr. Electr. Insul. 22(6), 3350–3356 (2016)
Chen, X., Wu, K., Wang, X., Cheng, Y., Tu, D., Qin, K.: Modified low density polyethylene by nano-fills as insulating material of DC cable(I). High Volt. Eng. 38(10), 2691–2697 (2012)
Khalil, M.S., Jervase, J.A.: Development of polymeric insulating materials for HVDC cables using additives: evidence from a multitude of experiments using different techniques. In: Conference Record of the IEEE International Symposium on Electrical Insulation, CA, USA (2000)
Murakami, Y., Imazawa, S., Kurimoto, M., Nagao, M., Inoue, Y., Reddy, C.C., Murata, Y.: DC breakdown characteristic on LDPE/MgO nanocomposite influenced by DC prestress. In: 2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, Cancun, Mexico (2011)
Murakami, Y., Nemoto, M., Okuzumi, S., Masuda, S., Nagao, M.: DC conduction and electrical breakdown of MgO/LDPE nanocomposite. IEEE Trans. Dielectr. Electr. Insul. 15(1), 33–39 (2008)
Zhao, H., Peng, S.Y., Yang, J.M.: Improving the dispersity and DC breakdown of MgO/LDPE nanocomposite by adding EVA. Adv. Mater. Res. 833(833), 339–342 (2014)
Li, Z., Du, B., Han, C., Xu, H.: Trap modulated charge carrier transport in polyethylene/graphene nanocomposites. Sci Rep.-UK 7(1), 4015 (2017)
Wang, Y., Wang, C., Chen, W., Xiao, K.: Effect of stretching on electrical properties of LDPE/MgO nanocomposites. IEEE Trans. Dielectr. Electr. Insul. 23(3), 1713–1722 (2016)
Xu, M., Zhao, H., Ji, C., Yang, J., Zhang, W.: Preparation of MgO/LDPE nanocomposites and its space charge property. High Volt. Eng. 38(3), 684–690 (2012)
Nilsson, F., Karlsson, M., Pallon, L., Giacinti, M., Olsson, R.T., Venturi, D., Gedde, U.W., Hedenqvist, M.S.: Influence of water uptake on the electrical DC-conductivity of insulating LDPE/MgO nanocomposites. Compos. Sci. Technol. 152, 11–19 (2017)
Zhao, N., Li, S., Wang, X., Li, G.: Effects of LDPE/nanofilled LDPE interface on space charge formation. In: IEEE International Conference on Solid Dielectrics (2013)
Min, D., Li, S., Ohki, Y.: Numerical simulation on molecular displacement and DC breakdown of LDPE. IEEE Trans. Dielectr. Electr. Insul. 23(1), 507–516 (2016)
Min, D., Li, S., Ohki, Y.: Analysis on the thickness and temperature dependent DC breakdown of low density polyethylene. In: 2015 IEEE 11th International Conference on the Properties and Applications of Dielectric Materials, (2015)
Wang, W., Min, D., Li, S.: Understanding the conduction and breakdown properties of polyethylene nanodielectrics: effect of deep traps. IEEE Trans. Dielectr. Electr. Insul. 23(1), 564–572 (2016)
Uvarov, V., Popov, I.: An estimation of correctness of XRD results obtained at analysis of materials with bimodal crystallite size distribution. CrystEngComm 17(43), 8300–8306 (2015)
Turnhout, J.V.: Thermally stimulated discharge of electrets. Polym. J. 2(2), 173–191 (1970)
Dissado, L.A., Fothergill, J.C.: Electrical degradation and breakdown in polymers. In: IEE Materials and Devices Series (1992)
Acknowledgments
This work was supported by the State Key Laboratory of Advanced Power Transmission Technology (Grant No. GEIRI-SKL-2018-010), the National Basic Research Program of China (grant No. 2015CB251003), and the National Natural Science Foundation of China (grant No. 51507124).
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Mi, R., Yan, C., Xing, Z., Wu, Q., Min, D., Li, S. (2020). Effect of Deep Traps and Molecular Motion on Dc Breakdown of Polyethylene Nanocomposites. In: Németh, B. (eds) Proceedings of the 21st International Symposium on High Voltage Engineering. ISH 2019. Lecture Notes in Electrical Engineering, vol 598. Springer, Cham. https://doi.org/10.1007/978-3-030-31676-1_102
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DOI: https://doi.org/10.1007/978-3-030-31676-1_102
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