The knowledge of partial discharge (PD) phenomena inside electrical insulation of power cables is an important issue for assessing the insulation condition and its degradation state, obtaining information about the likelihood of failure. PDs cause signals to propagate along the cable, as noise phenomena, and contribute to the insulation degradation, culminating in a disruptive fault with the interruption of power supply. Therefore, PDs are considered the best ‘early warning’ indicators of insulation degradation and their modelling, with the development of on-line PDs location methods, are important topics to increase the networks’ electricity security. In this study, a three-dimensional (3D) model of PD events using the CST STUDIO® Dassault software is proposed. PDs inside air inclusions in epoxy-resin are analysed with different shapes, positions and sizes of the defect. The electric-field distribution is evaluated with the conduction current inside the void and the apparent charges induced on the electrode. The effectiveness of the model is validated by comparing the simulation results with other published experimental results. Finally, a description of a 3D–1D hybrid model useful to describe the propagation of PD signals in power networks is given.

中文翻译：

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配电网和输电网中不同尺寸和位置的缺陷中局部放电的3D模型

了解电力电缆电绝缘内部的局部放电（PD）现象是评估绝缘状况及其退化状态，获取有关故障可能性的信息的重要问题。PD会导致信号沿着电缆传播，成为噪声现象，并导致绝缘性能下降，最终导致电源中断而造成破坏性故障。因此，随着在线PD定位方法的发展，PD被认为是绝缘退化的最佳“预警”指标，其建模是提高网络电力安全的重要主题。在这项研究中，提出了使用CSTSTUDIO®Dassault软件的PD事件的三维（3D）模型。分析了环氧树脂中空气中的PD的形状，缺陷的位置和大小。利用空隙内部的传导电流和在电极上感应的表观电荷来评估电场分布。通过将仿真结果与其他已发布的实验结果进行比较，验证了模型的有效性。最后，给出了可用于描述PD信号在电力网络中传播的3D-1D混合模型的描述。