Safety aspects in substation voltage uprating

It is noted that present arrester technology enables the use of smaller clearances and insulation levels than are currently standardized for HV substations. This permits voltage uprating or compacting of substations such that the substations can meet the safety standards. For the uprated substation it can be stated that if it met the safety standards before uprating, it would automatically meet the standards after uprating. However, the relevant standards could be improved to clarify the interpretation and promote flexibility of design. The working group on recommended clearances in substations has discussed the issues and set forth their views, which are intended to help the engineer involved with uprating/compacting safety. Brief comment on insulation coordination is given. The needed choice of BIL values for the same voltage rating in the HV range is supported, making the safety clearance issue straightforward