Method and apparatus for controlling an engine start system

An apparatus controls a synchronous machine used to start an engine during an engine start operation. The apparatus comprises: an exciter current control unit for controlling exciter current output to the synchronous machine during the engine start operation; and a main current control unit for controlling main current output to the synchronous machine during the engine start operation as a function of machine speed. In one implementation, the main current control unit controls main current output to the synchronous machine so that the synchronous machine exhibits a reduced output torque during an initial torque application stage. The reduced viscous drag effects and reduced impact torque are beneficial to the engine system.