Diesel electric hybrid buses are fairly common today in cities today. They combine electric motors with diesel engines to make the buses more efficient. They also use regenerative braking to recapture a portion of the kinetic energy the buses when they slow down. Now Cummins, a global leader in diesel engines, and TM4, a developer of electric powertrains, are partnering to bring a plug-in hybrid bus powertrain with a diesel range extender engine to urban bus fleets.
The two companies say that plug-in hybrid power can lower fuel consumption by at least 50% compared to a traditional hybrid bus. In addition to lower fuel costs, the new technology will provide transit authorities with a way to make some urban bus routes zero emissions zones.
The plug-in hybrid powertrain is composed of a Cummins Euro 2019 B4.5 diesel engine mated to a TM4 LSG130 electric generator, a 111 kWh lithium ion battery, a TM4 SUMO electric motor directly connected to the differential, a small fuel tank, and a battery management system. The buses will connect to a high power external charging network to recharge the batteries.
TM4 is a subsidiary of Hydro-Québec. It designs and manufactures electric motors, generators, power electronics, and control systems for commercial, automotive, marine, mining, rail, motorsports, and recreational vehicles. It has equipped 5000 buses in China with electric powertrain components last year.
“TM4 has always innovated to serve the market needs. Today, our customers can buy battery electric or hybrid buses with limited EV range. Our goal is to offer a system that can achieve 35 km EV range and benefit from the 450 kW fast charging infrastructure to recharge in less than 5 min. The range extender allows for peace of mind and significant flexibility. We are honored to be partnering with Cummins and hope to bring this product to market in the near future,” says Robert Baril, managing director of TM4.
For its part, Cummins will optimize the powertrain by selecting the most suitable engine to fill the role of range extender in a hybrid electric powertrain. “The close integration and control of the electrified powertrain with an appropriately selected engine is critically important to developing a plug-in hybrid electric vehicle system. We believe that through the team’s efforts we can become a significant player in electrification of commercial vehicles by providing complete systems to benefit our global customers.” says Wayne Eckerle, vice president of Cummins Research and Technology.
Source: Electric Cars Report