| Popis: |
In the medium-voltage range, circuit-breakers with vacuum as interruption medium have advantages such as environmental friendliness and lower maintenance costs compared to sulphur hexafluoride (SF6). Current political and industrial developments suggest an effort to expand the field of application of vacuum circuit breakers (VCB) up to high voltage levels. With a rising operating voltage level, the influence of parasitic capacitances on floating components, such as metal vapour shields, result in an increased absolute voltage drift of these components. This reduces the dielectric strength of the VCB, especially in case of lightning impulse stress. To ensure the dielectric strength of the high voltage VCBs, larger insulation distances are required. An approach with pure (linear) upscaling of all components and the gap distance is not sufficient from the technical as well as economical point of view. |
