Electro-Quasi-static Simulations for Space Charge and Electric Field Distribution in High-Voltage DC Cables

Project member
Christoph Jörgens, M. Sc.

Project duration
2016 - 2022

Keywords
electro-quasistatic fields, electric power transmission, high-voltage DC cable, nonlinear organic materials, space charges, charge injection, charge movement

Project description

During operation of high-voltage DC cables, the formation of so-called space charges in the insulating material can occur. These charges act as sources of electric fields and can lead to field excesses, which may cause the breakdown field strength of the insulating material to be exceeded. In order to prevent potential damage and thus ensure the reliability of the equipment, a detailed knowledge of the electric field distribution is necessary. This can be determined using numerical simulation methods. Considering that it may take days or weeks for a time constant space charge distribution to form in the insulating material, the simulation of the electric field distribution in a power cable can be considered as an electro-quasi-static field problem.

For this reason, this research project aims to develop a model of a power cable to simulate the electric field in order to investiagte and improve the reliability of high voltage DC cables. The objective is to imitate the charge motion in organic insulating materials by investigating and mathematically describing the drift and diffusion motion of individual charges, the injection of charge carriers and the charge behavior at a boundary layer of different dielectrics. In addition, the temperature distribution in a cable has to be taken into account, as the conductivity of the insulation depends on it. The level of the permissible operating temperature is investigated taking into account a thermal breakdown. The cable model is assessed by comparing the obtained simulation results with measurement results published in the scientific literature.

Project-related publications