Transient recovery voltages for station auxiliary system switchgear

A test circuit and test procedures were presented for measuring the transient recovery voltage (TRV) to which switchgear in electric generating plants will be subjected. The results of several TRV measurements at a generating plant on the Southern electric system were presented. The results indicated that the natural frequencies of the running or starting station service transformers were not significant. The frequency of the TRV depended only on the inductance of these transformers and the capacitance of the cables connecting the transformers to the switchgear bus. Significant damping of the TRV oscillations was recorded