New Flyer Industries has selected BAE Systems’ HybriDrive HDS300 propulsion system to power a fleet of new 60-foot, low-floor rapid transit buses for the Santa Clara Valley Transportation Authority (VTA) in San Jose, California. New Flyer Industries will provide up to 29 articulated hybrid buses for the transit agency, with an option for up to 20 additional buses at a later date. Articulated buses are comprised of a single-deck design with two rigid sections linked by a pivoting joint, allowing for higher passenger capacity.
The HDS300 articulated bus solution, which powers 60-foot transit buses, is the most recent addition to the HybriDrive Solutions product line. The HybriDrive family of products also includes the HDS100 European lightweight bus model and the HDS200 for 30- to 40-foot North American bus fleets.
Common to all HDS systems is the Modular Traction System (MTS), which comprises a traction motor/reduction gear and a traction generator to provide propulsion and power for the vehicle. The liquid-cooled, high power-to-weight ratio AC induction electric traction motor and reduction gear connect directly to a standard drive shaft and rear axle to provide traction power and regenerative braking.
The traction motor incorporates a fixed ratio planetary reduction gear, eliminating the need for a shifting transmission. This provides nearly jerk-free propulsion for the transit bus; resulting in a noticeably smoother and safer ride for passengers, especially standees, compared to conventional diesel or parallel hybrid buses.
The traction motor is the sole source of propulsion for the vehicle and is sized accordingly, providing high power and superior low-end starting torque. This gives HybriDrive-powered buses exceptional acceleration, performance on steep grades and efficiency of energy re-capture during regenerative braking.
The traction generator is coupled directly to the engine crankshaft, resulting in a compact bearingless design. The generator is sized to convert all engine crankshaft power to electrical power for use by the system, providing sufficient power for sustained highway operation at 65 mph.
The compact MTS occupies an equivalent space claim of a typical conventional transmission powertrain unit.The MTS can be installed in-line (T-drive) or transverse (V-drive). The simple design of the MTS reduces the cost of maintenance as well as the overall life cycle cost. MTS is available for HDS 100, HDS 200, and HDS 300 systems.
Power ratings for the HDS traction motor are 230 kW (peak); 200 kW (intermittent); and 180 kW (continuous).
Allowing transit authorities the commonality of using HybriDrive propulsion systems across all the buses in their fleets will reduce inventory and maintenance costs, providing more options for customers. For additional fuel and maintenance savings, the HybriDrive family of propulsion systems enables all bus accessories, such as air conditioning, power steering, and more, to run electrically.
The development and production of these hybrid propulsion systems will be conducted at BAE Systems’ Endicott, New York facility, with the first delivery scheduled for 2014.