SAN DIEGO, California — BAE Systems today introduced an improved version of its hybrid propulsion system that can be used on multiple bus platforms, is mechanically simpler, reduces maintenance costs, and makes possible the use of electric accessories.

The company unveiled its latest HybriDrive® propulsion system at the American Public Transportation Association’s Annual Meeting and Exposition in San Diego.

The new system, based on the company’s series diesel-electric hybrid technology already in use by transit agencies across North America, can be configured with the diesel engine and generator arranged inline or transversely to make it adaptable to a wider range of bus models. It also can generate power for electrically operated systems such as air conditioning, power steering, engine cooling, and lighting, serving these electrical loads without belt-driven alternators.

“We built upon the most proven heavy-duty hybrid technology to increase functionality, reduce maintenance costs, and provide more options to our customers,” said Rich Hopf, general manager of transport systems for BAE Systems in Johnson City, New York. “These improvements offer significant advantages and savings to transit agencies facing ever-increasing energy, environmental, and economic challenges.”

HybriDrive technology reduces emissions and increases fuel economy while meeting the durability requirements of demanding urban transit operations. The system consists of a generator, an electric motor, and an energy storage system managed by computerized controls. A diesel engine that turns the generator operates independent of the electric drive motor, allowing it to run at nearly consistent speed for optimum efficiency. The system also uses no mechanical transmission, a major maintenance item on traditional diesel buses.

The optional accessory power system in the new configuration can further improve efficiency and reduce maintenance by eliminating alternators and their associated pulleys and belts. The system can produce up to 27 kilowatts of electricity to run vehicle accessories and to enable the bus to be operated for brief periods in zero-emission mode, with the engine off. It also combines the starter and generator to eliminate the starter motor and flywheel, making the system simpler and lighter and further reducing maintenance requirements.

Buses equipped with the new hybrid system also will use a lithium-ion energy storage system that increases battery life and reduces vehicle weight, improving fuel economy and reducing emissions. The battery system is self-monitoring and easy to service for further savings in maintenance costs.

More than 1,500 buses powered by the HybriDrive system transport more than a million passengers daily in cities such as New York, San Francisco, Toronto, and London. To date, these buses have logged more than 70 million miles of revenue service, saved nearly 5 million gallons of diesel fuel and prevented more than 50,000 tons of carbon emissions. BAE Systems provides the systems for buses built by Alexander Dennis Limited, Daimler Buses North America, and New Flyer Industries.

BAE Syatems
06.10.2008