Equivalent circuits of transformers and reactors to switching surges

THE CALCULATION of switching surges occasioned by circuit-breaker operations requires that transformers, reactors, generators, and other apparatus be replaced by their equivalent circuits. To be of much practical use these equivalent circuits must be simple, as well as reasonably exact. Great accuracy, however, is not required — a 20-per-cent departure from exact values being regarded as tolerable. But the approximate circuit must be very simple; for it is merely one element in a network which may consist of many other elements, all of which enter into the equations which describe the switching surge.