Further shown in FIG. 1, a speed correcting gearbox 130 is operatively connected to the VFG configured to align generator frequency output to the second generator frequency output. A VFG control unit 112 is operatively connected to the generator 110 and to the electric module 106 configured to control the VFG 102 and a separate second generator control unit 113 is operatively connected to the second generator 111 and the HVDC Bus Network 106 configured to control the second generator. It is further conceived that speed correction can be located on high spool generator to align the frequency instead of the low spool.

The VFG 102 is operatively connected to a low-pressure spool gearbox 114 and the speed-correcting gearbox 110 is located between the VFG 102 and the low pressure gearbox 114. The second generator 111 is operatively connected to a high-pressure gearbox spool.

A method for controlling the system discussed above is also disclosed. The method includes driving alternating current from a first generator (VFG) connected to a low pressure gearbox spool resulting in a first frequency output, driving alternating current from a second generator connected to a high pressure gearbox spool resulting in a second frequency output and aligning the frequency output of the first generator to the frequency output of the second generator in order to control performance parameters of a direct current system of an aircraft. Aligning the frequencies is intended to reducing voltage ripple, and load ripple that is caused by misaligned frequency outputs.