Hylliion releases regenerative braking technology for tractors

The Hyliion system features a control box, APU and battery pack and it electrifies the rear axle on a tandem tractor axle to generate electricity through regenerative braking.

The Hyliion system features a control box, APU and battery pack and it electrifies the rear axle on a tandem tractor axle to generate electricity through regenerative braking.

One year after unveiling its regenerative braking system for trailers, Hyliion has actually flipped its script and brought a tractor version of the product to market first. A trailer model will follow next year. Hyliion announced the availability of its tractor system at the American Trucking Associations’ MCE show in Orlando this week.

CEO Thomas Healy told FreightWaves the whole premise of the business is to bring electrification to trucking. While electric trucks may be the wave of the future, they are not practical at this time in Class 8 operations, he said, due to the size of batteries needed to move a truck 600 miles in a day.

But, a hybrid solution like Hyliion offers not only introduces electric power to fleets, it saves fuel and cost. Healy said the 6x4 HE electric hybrid product achieves a 30% reduction in fuel use due to three factors. Fifteen percent is achieved through the hybrid technology, 12% from the system’s APU, and 3% from tractor aerodynamics. The Hyliion system comes with tractor aerodynamic panels from FlowBelow.

According to Healy, the add-on system electrifies the rear axle of a tandem axle tractor. Each time the vehicle brakes, the system collects that wasted kinetic energy and sends power into the battery pack or directly into the engine, as needed. Long haul trucks actually brake more than many people believe, Healy noted.

“Even if you are on cruise control, the cruise control will not let you speed, so it will apply the brakes, and then speed up,” he said.

The system also features a predictive terrain algorithm that uses maps to monitor the truck’s position relative to terrain. Should the system identify a downslope up ahead (it monitors up to 10 miles), and the battery is currently full, it will direct energy to the engine to reduce fuel usage knowing that it will recover that energy on the downslope.

Fuel savings varies based on individual operation. In addition, the APU can be used to power auxiliary items as needed to prevent idling.

Regenerative braking works by using an electric motor that applies force when the vehicle is going downhill or slowing down. When this occurs, coils in the motor create a magnetic field which applies negative torque on the axle. This negative torque produces a current which recharges the Hyliion battery. This energy creation is about 90% efficient. When the vehicle accelerates or is going uphill, the electric motor provides power to reduce the load on the diesel engine.  

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