In this system, the supply is taken from the alternator itself through a 3-phase star/delta connected step-down transformer. The primary of the transformer is connected to the alternator bus and their secondary supplies power to the rectifier and also feed power to the grid control circuit and other electrical equipment.
This system has a very small response time and provides excellent dynamic performance. This system reduced the operating cost by eliminating the exciter windage loss and winding maintenance.
