RHODaS: New solutions to improve the efficiency of electric propulsion systems for heavy vehicles

Road transport that uses fossil fuels in internal combustion engines currently generates almost 60% of all emissions released into the atmosphere by human activity. Although private cars are the main source of contamination, light and heavy vehicles represent almost 40% of total CO2 emissions for mobility on roads in Europe. Thus, the electrification of these vehicles, especially heavy vehicles, is key to limit environmental pollution and contribute to mitigating the effects of climate change.

In 2020, lorry manufacturers in the European Union (EU) and members of the European Automobile Manufacturers’ Association (ACEA) made a commitment to decarbonise the sector before 2050. To achieve this, lorry manufacturers are investing in new solutions, such as alternative fuels, batteries or hydrogen. Battery-powered electric vehicles are the first zero-emissions technology that has reached the market of lorries, followed by hydrogen-powered lorries. However, there are still no integrated, compact, high-efficiency components of the propulsion system for the different models and types of vehicles that exist. For this reason, the RHODaS European research project was launched.

The Motion Control and Industrial Applications (MCIA) centre, the Terrassa Industrial Electronics Group (TIEG) and the Environmental Engineering (ENMA) group of the Universitat Politècnica de Catalunya - BarcelonaTech (UPC) participate in RHODaS (Reinventing High-performance pOwer converters for heavy-Duty electric trAnSport), a project to improve integrated motor propulsion systems for multiple drive architectures with more efficient materials, new semiconductors, better heat management and standardisation of manufacture of power convertors. All this will increase the efficiency of the architecture, the power density, the reliability, the cost and the sustainability of long-distance electric vehicles. 

To achieve this, the prototype of a modular power convertor with GaN (gallium nitride) and SiC (silicon carbide) devices will be developed. New semiconductor materials will be included, which will contribute to reducing the weight and size. Furthermore, the prototype will include sensors that will gather data for the design of a digital twin. Through artificial intelligence applied to control and diagnosis, this will enable predictive maintenance of the system and its components. In turn, this will contribute to increasing the efficiency and performance of the whole. In this way, the requirements of design, manufacture, performance and safety will be brought together, to create a profitable value chain for the European Union, based on economies of scale as a competitive advantage over Asian and US manufacturers. 

Concepts such as ecodesign and circularity will be applied in the manufacturing strategies and determination of useful life (repair, reuse, reconditioning and recycling) of the components. This will be achieved through the use of digital tools such as 3D design and simulation of modular power electronics. 

MCIA leads the tasks of integrating the electric drive system and the control electronics. TIEG is responsible for the design of electric and electronic components of the project, and specifically the T-type hybrid GaN-SiC convertors. Finally, ENMA is responsible for reviewing the environmental impact studies and the circular design of the convertors.