BAE Systems is developing a parallel hybrid propulsion system designed for medium- and heavy-duty truck applications. The parallel system is the latest version of the company's HybriDrive green propulsion system.

The HybriDrive series propulsion system -- currently in service on more than 3,000 transit buses in cities around the world -- meets the demands of urban transit duty cycles, which require low average speeds and frequent stop-and-go operation. The HybriDrive parallel system is designed to address the needs of vehicles with duty cycles that require higher operating speeds and less frequent stops.

"The development of a parallel system is part of our strategy to broaden our HybriDrive product family to meet the growing worldwide need for more efficient transport and energy management," said Steve Trichka, general manager of power and energy management for BAE Systems. "Our HybriDrive parallel system is the perfect hybrid electric solution for vehicles that operate in diverse duty cycles beyond standard urban operational modes."

With more than 200 million miles of revenue service, more than 10 million gallons of diesel fuel saved, and more than 100,000 tons of carbon dioxide emissions prevented, the HybriDrive series system has proven itself to be a very efficient hybrid systems for the transit bus sector and has provided significant environmental benefits, BAE claims.

HybriDrive series and parallel technologies both use simplified and proven components and controls to deliver their capabilities. While the series system does not use a transmission, the HybriDrive parallel system is based on a single electric machine integrated between the engine and the transmission. The system can be installed with minimal impact to the vehicle, and enhances propulsion through an optimized blending of internal combustion engine power and electric power. The system's energy management and control capabilities ensure all energy flow -- such as propulsion and regeneration -- occurs in the most efficient fashion.

"HybriDrive power is green power, and our new parallel system addresses the need for more efficient, cleaner, medium- and heavy-duty transport of goods and people around the world," Trichka said. "Further, our carefully crafted strategic partnerships have established wide global distribution, experienced customer-service and field-support structure for this new technology."

The HybriDrive parallel system, in final stages of development, will see its first road trials next spring and is expected to be deployed in markets around the world in 2012.

More info: www.baesystems.com.