TAP CHANGING APPARATUS HAVING A GATE CONTROL TRIPPER

摘要

Tap changing apparatus including a transformer having a tapped winding, solid state switching elements connected between the winding and a load, and a control circuit which provides the proper gate drive to the switching elements for changing taps. The control circuit senses the voltage and current characteristics of the system to determine at what instant it will gate the switching elements in making a tap change. A tripper circuit senses the system current and trips the control circuit so that a tap change cannot be made when the system current is too low to have its characteristics detected.