Substation voltage uprating: design and experience

Uprating of substations (i.e. conversion from a lower rated voltage to a higher rated voltage without complete rebuilding) can be accomplished through sound insulation coordination. The authors provide a step-by-step procedure for insulation design of uprated substations, including two examples of recently uprated substations by Public Service Company of Colorado (PSCC) and El Paso Electric Company (EPE). PSCC´s substation is at 6000 ft elevation and it was uprated from 115 kV to 230 kV utilizing existing 550 kV BIL equipment. EPE´s substation is adjacent to a steel plant with a high level of contamination and it was uprated from 69 kV to 115 kV utilizing existing 350 kV BIL equipment. The authors consolidate the experience of the above utilities and others to present an up-to-date summary of the substation uprating activities in North America