주변압기 용량증설에 따른 배전계통의 차단기 정격차단전류 검토

An Investigation of the nominal rating current for breakers in distribution system due to the increased capacity of power transformer

In order to evaluate the nominal rating of breakers in distribution system due to the increased capacity of power transformer from 60 to 100 MVA, the fault currents are calculated in the condition of 3-phase fault and single line-to-ground fault. Consequently, under the condition of the parallel operation of transformers the fault currents were exceed the nominal rating current of breakers in some areas.