Insulation coordination of HV equipment in 115 kV AIS substation: Case study in Thailand

This paper presents an insulation coordination of high voltage Equipment in 115 kV AIS Substation in Thailand. In the analysis according to IEC60071-2, a suitable insulation level and electrical clearance of the equipment are determined. The actual data of all equipment in substation such as technical data, load and fault levels of the sample substation are entered in the simulated circuit and the simulation is performed by using ATP/EMTP program. Overvoltages such as temporary and slow-front are observed in different switching operations. The effect of switching overvoltage from neighboring substation has also been considered for determining the insulation levels and clearances. The obtained results are used as a guideline for selecting the proper voltage rating of new high voltage equipment in a new or renovated/refurbished substation.