In-situ arc fault testing on MV substation

This paper deals with the effects of an arc fault in the medium-voltage switchgear of a transformer substation (distribution substation), a common part of an electrical distribution grid. These transformer substations are widely used to step down medium voltage to low voltage and supply end-customers.The focus of the considerations is the pressure load caused on the inside of the electrical distribution substation building. For existing buildings made of masonry, hardly any literature is available taking the dynamic of the pressure load into account. However, available limit values for static pressure load might be exceeded. Due to the lack of accurate assessment methods for arc pressure loading by structural engineers, conservative approaches must be used. The costly consequence is that either great efforts must be made to limit the pressure or the distribution substation hast to be rebuilt. Therefore, an in-situ test was performed on a masonry transformer station to gain new insight into the pressure load capacity of masonry due to arcing events. The results show a higher load capacity of masonry than assumed.