A Modified Algorithm for the Simulation of Charge Behavior in Water Tree Aged Cross-Linked Polyethylene Cable

作者：Zhang, Yu; Liu, Deyuan; Wu, Jiandong^*; Yin, Yi

来源：IEEE Access, 2018, 6: 23929-23938.

DOI：10.1109/ACCESS.2018.2830402

• Water tree
• XLPE
• space charge
• Crank-Nicolson
• bipolar charge transport model
• cable insulation
• algorithm design and analysis

In this paper, a modified algorithm is introduced to explain the process of charge formation in water tree aged cable insulation with respect to the dielectric properties of water tree areas and the cylindrical geometries of cable insulation. The algorithm combined with the classic bipolar charge transport model represents a novel attempt to simulate charge behavior in insulation with water tree. The finite-difference method is employed to solve for the electric field in the presence of space charge, and the finite-volume method is employed to solve the charge continuity equation. The dielectric parameters in this paper are not instantaneous near the interface but are functions of the radius. To overcome the Courant-Friedrichs-Lewy condition, the Crank-Nicolson method is used to separate the governing equations in the time domain. To validate the accuracy of the model, this paper also presents the space charge behavior in water tree aged cross-linked polyethylene cable samples measured by the full-scale pulsed electro-acoustic method. The homocharge is injected under a high electric field. During the depolarization process, the shallow trap charge gradually disappears, whereas the homocharge continues to form a positive peak signal. Simulations show that the homocharge accumulates in the tip of the water tree because the dielectric characteristics of the material change during the water-aging process. The model describes the behavior of space charge in the water tree aged insulation of cylindrical geometries. Improvements will be needed in the following research.

• 出版日期2018
• 单位上海交通大学