Abstract
In view of the finiteness of fossil energy sources, the CO2 discussion and political constraints regarding emission limitations of motor vehicles, the OEMs have focused on the development of alternative drive concepts for several years. The parallel hybrid drive, with different ver-sions already being on the market, is one of these concepts.
The state of the art for evaluating and comparing energy and fuel consumption is determined in statutory driving cycles, e.g. the New European Driving Cycle (NEDC). These values, however, hardly comply with the values determined in practice due to the different perform-ance requirements in driving cycle and customer use. It is therefore necessary to focus on the requirements determined in representative customer use instead of statutory driving cycles to increase the drivetrain efficiency and achieve maximum customer benefit. In this regard, a holistic approach will be presented, which takes the driver behaviour in real traffic into ac-count. It is based on the so-called 3D parameter space which is defined by three variables: driver, driven vehicle and driving environs. The driver is differentiated in terms of driving style. „Driven vehicle‟ takes the system behaviour of the hybrid drive train into account and „driving environs‟ describes where the vehicle is driven (road, traffic control etc.).
The following aspects are most important: use of the 3D method to determine the representa-tive requirements on the drivetrain components of parallel hybrid drives and the appropriate representation of the results of extensive simulations in NEDC and customer use. In addition to potential fuel savings, loads on the drivetrain components (e.g. transmission and start/stop clutch) in NEDC and customer use are compared.
Keywords: parallel HEV, simulation, customer, requirements, driving cycles