Tractor unit with on-board regenerative braking energy storage for stopover HVAC operation without engine idle
A through the road (TTR) hybridization strategy is proposed to facilitate introduction of hybrid electric vehicle technology in a significant portion of current and expected trucking fleets. In some cases, the technologies can be retrofitted onto an existing vehicle (e.g., a trailer, a tractor-trailer configuration, etc.). In some cases, the technologies can be built into new vehicles. In some cases, one vehicle may be built or retrofitted to operate in tandem with another and provide the hybridization benefits contemplated herein. By supplementing motive forces delivered through a primary drivetrain and fuel-fed engine with supplemental torque delivered at one or more electrically-powered drive axles, improvements in overall fuel efficiency and performance may be delivered, typically without significant redesign of existing components and systems that have been proven in the trucking industry.
1. A tractor for use in a tractor-trailer vehicle configuration, the tractor comprising:
at least one electrically-powered drive axle coupled to a frame of the tractor and configured to supply supplemental torque to one or more wheels of the tractor, while the tractor-trailer vehicle travels over a roadway and in at least some modes of operation;
a battery on the tractor, the battery configured to:
supply, in a first mode of operation, electrical power to the electrically-powered drive axle, and
receive, in a second mode of operation, energy recovered from the electrically-powered drive axle using regenerative braking;
a controller in communication with the at least one electrically-powered drive axle, the controller to:
receive sensor inputs from a plurality of different types of sensors,
compare the plurality of sensor inputs to predetermined, corresponding threshold values, and
control the at least one electrically-powered drive axle to select one of the first mode of operation, the second mode of operation, or a third mode of operation based on the sensor inputs; and
a heating, ventilation or cooling (HVC) system on the tractor-trailer vehicle, the HVC system coupled to receive electrical power from the battery.
2. The tractor of claim 1 , further comprising:
at least one fuel-fed engine powered drive axle coupled to the frame of the tractor, wherein the at least one fuel-fed engine powered drive axle is coupled via a drive shaft to a fuel-fed engine to drive at least a pair of wheels and to thereby provide primary motive forces.
3. The tractor of claim 1 , wherein the HVC system is an auxiliary system, substantially separate from a main heating ventilating or cooling system of the tractor, configured to regulate temperature within at least a portion of a cabin of the tractor unit during stopover and without idling of the fuel-fed engine.
4. The tractor of claim 1 , wherein the tractor is a 6×2 tractor unit retrofitted to replace an otherwise dead axle of a tandem pair with the electrically-powered drive axle.
5. The tractor of claim 4 , wherein the retrofitted electrically-powered drive axle is coupled to a brake line of the tractor unit for control of the regenerative braking mode of operation.
6. The tractor of claim 1 , further comprising:
a battery management system for controllably maintaining a desired state of charge (SoC) of the battery array during the over-the-roadway travel; and
a heat exchanger for at least moderating temperature of the battery during the over-the-roadway travel.
7. The tractor of claim 6 , further comprising:
an in-cabin control interface coupled to the battery management system, the control interface including:
an in-cabin display of state of charge for the battery array; and
mode control for selectively controlling an operating mode of the battery management system, wherein in at least one selectable mode, energy recovered using the electrically-powered drive axle in the regenerative braking mode is used to bring the battery array to a substantially full state of charge, and wherein in at least another selectable mode, state of charge is managed to a dynamically varying level based on actual or predicted requirements for supplemental motive forces during over-the-roadway travel.