Hybrid propulsion system power management

A system comprising:

• an electrical energy storage system (ESS) configured to output electrical power onto a direct current (DC) electrical distribution bus;
• one or more electrical generators configured to output electrical power onto the DC electrical distribution bus, wherein the one or more electrical generators are configured to convert mechanical energy into electrical energy;
• one or more electrical propulsion units configured to propel a vehicle using electrical power received via the DC electrical distribution bus;
• and
• one or more processors configured to:
• receive a power demand that specifies an amount of power to be used to propel the vehicle;
• determine, based on the power demand and a predetermined ESS output limit, a first amount of power to be sourced from the ESS and a second amount of power to be sourced from the one or more generators;
• and
• cause the ESS to output the first amount of power onto the DC electrical distribution bus and cause the one or more electrical generators to output the second amount of power onto the DC electrical distribution bus.