Christoph Danzer

Comparison and Evaluation of a New Innovative Drive Concept for the Air Conditioning Compressor of Electric Vehicles

The development of energy efficient air conditioning systems for electric vehicles is an ever increasing challenge, because the cooling as well as the heating of the passenger compartment reduces the cruising range dramatically. Almost always the compressor of the air conditioning system in electric cars is a scroll compressor with a separate electric motor and appropriate power electronics. However, this solution is critical in terms of the installation space, the weight and also the costs. Therefore, IAV is developing an innovative and energy efficient drivetrain structure for electric vehicles, which integrates the motor of the air conditioning compressor directly into the drivetrain of the vehicle. Thus it is possible to switch off the compressor motor and to use the main motor for the drive of the air conditioning compressor at certain driving situations. As a result, the operating point of the main motor can be shifted to a better efficiency. This leads to a reduced power loss and an enhanced cruising range. In addition, the compressor motor can be used to contribute to the powertrain of the vehicle, as well, if the efficiency of the compressor motor is higher than the efficiency of the main motor, e.g. in urban traffic. Thereby the efficiency and the cruising range of the vehicle can be increased. This contribution presents a new powertrain concept which realizes the above mentioned mechanical coupling of the main motor and the compressor motor. Moreover, the simulation models developed for the air conditioning system, the passenger compartment and the drivetrain of electric vehicles are introduced. These models were used to compare an electric vehicle equipped with the new powertrain concept with a common electric car with a separate scroll compressor. Both systems are evaluated by means of the achievable cruising range for different driving cycles and environmental conditions.

75 g CO 2 / km – powertrain concept and optimized powertrain components

Zukunftige Abgasgesetzgebungen sind durch rein Verbrennungsmotorische Antriebe in Kombination mit Verringerung der Aggregatevielfalt, Downsizing und standardisiertem Einsatz vom Kleinwagen bis zum SUV nur schwer zu erreichen.

Optimal hybrid gasoline engine – solutions for complex powertrains

To meet the many and various development targets in relation to CO2, emissions, performance, comfort, weight and costs for 2025 and 2030, manufacturers are looking for the most sustainable scenarios in the context of fleet demands, modular systems and production costs. The powertrain plays a key role in this regard. Fundamental decisions have far-reaching consequences, and correcting those leads furthermore to an enormous effort. The complexity of the goals, demands and boundary conditions is so high that optimizing the powertrain’s components with conventional development methods is no longer sufficient.