Energy Efficient Vehicles for Road Transport

Abstract

Road transport is the second largest producer of greenhouse gases within the European Union. This project, Energy Efficient VEhicles for Road Transport (EE-VERT) targets a 10-12% reduction in fuel consumption and CO2 generation for conventional vehicles with only minimal changes. Hybrid Electric Vehicles (HEVs) and Full Electric Vehicles (EVs) offer good CO2 savings but their market penetration is slow, therefore conventional vehicles will play a significant role for the foreseeable future. Despite improvements in modern conventional vehicles, a considerable amount of energy is wasted due to the lack of an overall on-board energy management strategy. Electrification of auxiliary systems and operating them only when needed promises energy and efficiency gains, but there is an additional need for a coordinated approach to the generation, distribution and use of energy. EE-VERT offers a solution to bridge the gap in the market between present conventional vehicles and HEVs/EVs. The central EE-VERT concept is the electrification of auxiliary systems and supplying their energy from energy sources such as recuperated braking energy, waste heat recovery or solar cells, as part of an overall energy management strategy. The conventional car uses a 14V network and the EE-VERT concept retains the majority of this to minimise additional costs. However, to achieve improved efficiency and power, the generator operates at 40V. To connect the elements to the standard electrical system a new architecture has been devised that works with 40V and 14V levels. The main components of the 40V network are a new generator based on the claw pole technology with integrated permanent magnets, a Li-Ion battery system and a DC/DC converter with multiple inputs (MIPEC) for interfacing between the two voltage levels and the additional energy sources such as the solar panel. The available generator power during recuperation is up to 11kW. The efficiency of the new generator is above 80% in the low range of speed while in the high range of speed the efficiency is still above 70%. The MIPEC efficiency is around 94%. The simulation work indicates that average fuel savings of 10% for real life driving cycles and up to 17% when the start and stop functionality is applied to real life urban cycles are possible and that real life urban driving cycles benefit the most from the EE-VERT concept. The final phases of the project work on the Test Bench and with the demonstrator car will confirm the potential fuel saving benefits of the EE-VERT concept.