Method and system for controlling synchronous machine as generator/starter

A synchronous brushless machine having a single exciter field stator winding. The single exciter field stator winding is energized by a high frequency alternating current to provide a single excitation field to magnetically couple with the exciter field armature winding in both the starter mode and the generator mode. With a higher excitation frequency relative to the main armature current frequency, a steady main field voltage can be achieved which improves stability control while in the starter mode. In one or more configurations, the single exciter field stator winding is driven by an H-bridge converter.