Abstract Cross-linked polyethylene (XLPE) insulated power cables are widely used in transmission and distribution networks. The enhanced localised electrical field/stress can result in surface discharges (SD), i.e. partial discharges on the surface of the dielectric. To measure discharges, very low frequency (VLF-0.1 Hz or lower) excitation has emerged as an attractive alternative to the conventional power frequency (PF- 50/60 Hz) testing as it significantly reduces the required reactive power from the test supply. As the discharge process mainly resulted from the enhanced electric stress; it is necessary to understand how the electric field distributes on the XLPE dielectric surface when it is exposed to a high voltage AC excitation. In this study, the distribution of surface electric field before, during and after a PD event at VLF and PF test voltage is investigated. Finite element analysis (FEA) based numerical simulation shows that the space charge dynamics cause the differences in the field distribution and supports the experimental results.

中文翻译：

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局部放电测试交联聚乙烯绝缘表面电场分布

摘要 交联聚乙烯（XLPE）绝缘电力电缆广泛应用于输配电网络。增强的局部电场/应力可导致表面放电(SD)，即电介质表面上的局部放电。为了测量放电，极低频（VLF-0.1 Hz 或更低）激励已成为传统电源频率 (PF-50/60 Hz) 测试的有吸引力的替代方案，因为它显着降低了测试电源所需的无功功率。由于放电过程主要是由增强的电应力引起的；有必要了解电场在 XLPE 电介质表面暴露于高压交流激励时如何分布。在本研究中，之前的表面电场分布，研究了在 VLF 和 PF 测试电压下的 PD 事件期间和之后。基于有限元分析 (FEA) 的数值模拟表明，空间电荷动力学导致场分布的差异并支持实验结果。