System and methods for stabilization of DC bus voltage in a hybrid-electric aircraft

A system comprising:

• a direct current (DC) bus;
• an engine;
• an electric generator configured to receive mechanical power from the engine and generate first alternating current (AC) power;
• a first inverter configured to convert the first AC power to DC power and output the DC power to the DC bus;
• and
• a controller configured to control the engine to increase or decrease the AC power output by the electric generator,
• a second inverter configured to receive DC power from the DC bus and convert the DC power to second AC power for use by an electric motor of an aircraft,
• wherein the DC bus is configured to attach to at least one battery pack or supercapacitor,
• wherein the at least one battery pack or supercapacitor is configured to maintain a nominal voltage of the DC bus approximately at a nominal battery pack voltage of the at least one battery pack, and
• wherein the DC bus is further configured to attach to at least one electric motor configured to supply power to a propulsion mechanism of an aircraft.

A method of controlling voltage of a DC bus of an aircraft comprising:

• connecting at least one battery pack or supercapacitor to the DC bus, wherein the at least one battery pack or supercapacitor is electrically directly connected to the DC bus;
• controlling, by a controller, mechanical power output by an engine to an electric generator, wherein the electric generator outputs first alternating current (AC) power from the mechanical power output of the engine;
• converting, by a first inverter, the first AC power from the electric generator to direct current (DC) power;
• outputting the DC power from the first inverter to the DC bus;
• controlling, by the controller, a second inverter configured to convert the DC power from the DC bus to second AC power and supplying the second AC power to drive an electric motor of the aircraft, wherein at least one battery pack or supercapacitor is configured to maintain a nominal voltage of the DC bus approximately at a nominal battery pack voltage of the at least one battery pack;
• and
• determining:
• that the second AC power used by the electric motor is presently above or will be above a predetermined threshold;
• or
• that an actual voltage of the DC bus or an actual current flowing through the DC bus is outside of a predetermined desirable range.