Switching overvoltages in line-transformer and cable-transformer cascades

Overvoltages in a transformer can be generated by switching events either at the terminals of the transformer or in the connected power system. The objective of the study is to formulate a method of calculating the distribution of transient voltages at different points of line-transformer and cable-transformer cascades. A detailed three-phase mathematical model of the line, cable and transformer is used. The overvoltages for a variety of transformer connections are obtained, and it is established that the presence of a line or cable at the transformer terminals reduces the peak overvoltages