Electromagnetic field and force analysis of three-phase enclosure type GIS bus capsule

With the aim to optimization design and condition monitoring of GIS, a 3-D finite element model has been used for the computation of the electromagnetic field and forces in a three-phase enclosure type gas insulation station (GIS) bus capsule. The calculation takes into account the bus bar connector´s contact resistance and physical properties of the materials involved. Using the field distributions, the eddy power losses and the electromagnetic forces have been calculated. The influence of the operation current and short current on these quantities is also examined. The distributions of current density and electromagnetic force in the conductors and tank are not uniform. The electromagnetic forces of bus conductors are large enough to overcome hold forces exerted by the contact springs under short circuit conditions.