The landscape of electric drive technology for heavy-duty commercial trucks is evolving rapidly, with recent strides in power electronics leading the charge. Notably, advancements in power systems, such as inverters, are driving increased efficiency and compactness. The adoption of silicon carbide (SiC) and gallium nitride (GaN) semiconductors in power electronics is revolutionizing the field, offering superior thermal and electrical properties that enable higher power densities and more effective thermal management.
Despite these advancements, challenges persist in integrating these cutting-edge power systems into existing truck architectures. One significant area of focus is electric transmission, which plays a crucial role in optimizing propulsion system efficiency across diverse driving conditions. While single-speed transmission, prevalent in electric vehicles (EVs), maximizes motor performance within its optimal range, multi-speed transmission offers enhanced performance, efficiency, and range, especially for heavy loads and steep gradients.
In a bid to address these challenges, BAE Systems and Eaton recently conducted tests on their integrated electric drive system for medium- and heavy-duty trucks. This collaborative effort combines BAE’s advanced electric motor and power electronics expertise with Eaton’s HD or MD 4-speed EV transmission, showcasing a promising leap forward in heavy-duty electric propulsion.
BAE’s modular advanced power electronics lie at the heart of this electric drive solution. The architecture, characterized by fewer components, cables, and connections, not only saves space and weight but also simplifies OEM integration and reduces overall costs. Leveraging SiC and GaN devices enhances heat management, reduces weight, and increases power density, while the use of interchangeable component modules streamlines design and assembly, resulting in 50% fewer connections and cables compared to conventional systems.
The collaboration between BAE Systems and Eaton underscores their commitment to supporting commercial electric trucks. Initially focused on the medium-duty truck market, their partnership has expanded to include heavy-duty commercial trucks above 19 tons, catering to a wide range of applications, including delivery trucks, regional haulers, and buses.
By combining BAE’s electric motor and high-power density power modules with Eaton’s HD 4-speed EV transmission, the integrated electric drive system offers a comprehensive solution for heavy-duty EVs. Testing conducted on a Class 7 demonstration vehicle at Eaton’s proving grounds in Michigan demonstrated the system’s ability to meet key on-road performance milestones, marking a significant milestone in the advancement of electric propulsion technology for commercial trucks.