ABSTRACT
The flicker of the house lights while having dinner is a sign of a load tap changer (LTC) tap change. When most people get home from work, they start using electricity for cooking and lighting. The latter signals the LTC to change taps to adjust the voltage back to its nominal value with some tolerance. An LTC is a device that connects different taps of tapped windings of transformers without interrupting the load. It must be capable of switching from one tap position to another without at any time interrupting the flow of the current to the load and without at any time creating a short circuit between any two taps of the transformer winding. An LTC must be capable of switching from one tap position to another without interrupting the flow of current to the load at any time. It must therefore follow a "make-before-break" switching sequence.
