Electric field computation of ±1000 kv dc wall bushing with consideration of space charge effects

+/- 1000kVDC wall bushing under planning is a complex insulation system which bears the effects imposed by different working conditions. The existence of space charge distorts the electric field distribution, which might result in electric breakdown especially when polarity reversal occurs. Based on space charge theory, the amount of space charge can be calculated. A finite-element model for +/- 1000kVDC wall bushing is established to analyze the electric field distribution under DC, AC and polarity reversal conditions especially considering the space charge effects. The electric field distribution with thermal stress is also calculated in this paper to incorporate the influence of the dielectric temperature gradients. The research results provide useful reference for electric field computation and further insulation optimization in developing ultra high voltage DC wall bushings. Copyright (c) 2013 John Wiley & Sons, Ltd.