Systems and methods involving variable speed generators

A variable frequency generator (VFG) exciter comprising:

• a first converter, operative to convert DC current to AC current connected to a DC link;
• and
• a second converter, operative to convert DC current to AC current connected to the DC link, wherein the second converter is electrically connected to a generator rotor;
• a first switch operative, when closed, to connect the first converter to a stator portion while a generator is operating in a starting condition, wherein the first switch is open while the generator is operating in a running condition;
• and
• a second switch operative, when closed, to connect the first converter and the second converter in parallel, to the rotor portion while the generator is operating in a running condition, wherein the second switch is open while the generator is operating in the starting condition.

A method for starting and operating a VFG system, the method comprising:

• closing a first switch, wherein the closed first switch is operative to connect a first converter to a stator of a generator;
• starting the first converter, wherein the first converter is operative to convert DC power to AC power and control the stator;
• starting a second converter, wherein the second converter is electrically connected to a rotor, and is operative to convert DC power to AC power and control the rotor;
• starting a generator;
• opening the first switch, thereby disconnected the first converter from the stator;
• closing a second switch, wherein closing the second switch connects the first converter and the second converter in parallel;
• and
• controlling the first converter and the second converter to operate in parallel to send power to the rotor.