Locomotive propulsion system

A vehicle propulsion system comprising:

• a vehicle platform;
• plural axles and wheels operably coupled to the platform;
• a traction motor attached to the platform and operably coupled to at least one of the axles;
• a propulsion electrical storage device electrically connected to the traction motor via a propulsion circuit, the propulsion electrical storage device configured to power the traction motor to provide tractive effort to propel the vehicle along a route;
• an ancillary electrical storage device electrically connected to the traction motor via an ancillary circuit, the ancillary electrical storage device being a different type of electrical storage device than the propulsion electrical storage device;
• and
• a controller having one or more processors and operatively connected to the propulsion circuit and the ancillary circuit, wherein the controller is configured to direct the ancillary electrical storage device to supply electric current to the traction motor via the ancillary circuit to power the traction motor during an elevated demand period, wherein, at an end of the elevated demand period, the controller is configured to control the ancillary circuit to stop conducting electric current from the ancillary electrical storage device and to direct the propulsion electrical storage device to supply electric current to the traction motor via the propulsion circuit to power the traction motor.

A vehicle propulsion system comprising:

• a vehicle platform;
• plural axles and wheels operably coupled to the platform;
• a traction motor attached to the platform and operably coupled to at least one of the axles;
• a propulsion electrical storage device electrically connected to the traction motor via a propulsion circuit, the propulsion electrical storage device configured to power the traction motor to provide tractive effort to propel the vehicle along a route;
• an ancillary electrical storage device electrically connected to the traction motor via an ancillary circuit, the ancillary electrical storage device being a different type of electrical storage device than the propulsion electrical storage device;
• and
• a controller having one or more processors and operatively connected to the propulsion circuit and the ancillary circuit, wherein the controller is configured to direct the ancillary electrical storage device to supply electric current to the traction motor via the ancillary circuit to power the traction motor during an elevated demand period, wherein, at an end of the elevated demand period, the controller is configured to control the ancillary circuit to stop conducting electric current from the ancillary electrical storage device and to direct the propulsion electrical storage device to supply electric current to the traction motor via the propulsion circuit to power the traction motor,
• wherein the ancillary electrical storage device charges and discharges faster than the propulsion electrical storage device, and the propulsion electrical storage device has a greater energy storage capacity than the ancillary electrical storage device.