In order to reduce emissions a variety of efforts in ancillary electrification und powertrain operation strategies have to be made in the near future. Examples for effcient powertrain functions are Auto-Start-Stop (ASSF) and Brake Energy Regeneration (BER) implemented in so-called 'Micro-Hybrid-Vehicles'. Electric power steering (EPS) is an exemplary application for ancillary electrification, which is already in common use. As a consequence of these measures the demand for electrical power and energy increases in the near future for electrical vehicle dynamics, powertrain, driver assistance and consumer functions. The common 12 V power net will be overstressed and effects like reduced battery lifetimes and critical undervoltage levels can be expected in future power nets. Depending on the particular need of power, different voltage fluctuations result from the functions mentioned above in a regular power net. As an example, the Auto-Start-Stop function ASSF reduces the supply voltage below the regular minimum of 9 V at each engine start. The voltage fluctuations are observed especially in operation modes with limited capability, e.g. deeply discharged batteries or low generator speed. The characterization of the power net architectures discussed here was performed under varying load profiles. The profile consists of increasing steps in amplitude (1 to 4 kW) and duration (0,3 to 3 s) of power request. The experimental setup was arranged according to figure 3, the applied cable lengths and cross sections were dimensioned according to the condition of a load (e.g. electrical power steering) in the front end and power net extension and primary battery in the rear end of the vehicle, respectively. A 90 Ah lead acid battery with a System-on-Chip (SoC) of 50 % was used as primary battery. The measurements were performed at room temperature. During measurement the primary battery was supplied with a constant current of 5 A. In summary the power net extensions investigated here represent powerful 'plug-in' measures and improve the power supply even under the progression of electrification and CO2 -efficient operation modes in future vehicles. Depending on the particular vehicle configuration different combinations of the discussed power net extensions VSU (vehicle steering unit), DPA, PNE I (power net extension I) and PNE II can be applied: The VSU shows some practical effect in stabilizing critical loads at ASSF operation but without active support of high power loads or the primary power net. The PNE I represents an effective power supply for high power loads in vehicle dynamics or steering systems with low average and high peak power demand. Further requirements in brake energy regeneration and auto-start-stop function ('Micro-Hybrid') can be fulfilled by a PNE II system.
Advanced power net architecture for BMW micro-hybrid vehicles
Bordnetzerweiterung zur Energieversorgung CO2-optimierter Funktionen bei BMW
2009
12 Seiten, 7 Bilder, 1 Tabelle, 10 Quellen
Aufsatz (Konferenz)
Englisch
Advanced power net architecture for BMW micro-hybrid vehicles
Kraftfahrwesen | 2009
|Advanced control architecture for autonomous vehicles
SPIE | 1997
|MODULAR FUEL CELL POWER SYSTEM ARCHITECTURE FOR HYBRID VEHICLES
Europäisches Patentamt | 2023
|Advanced ultralight hybrid-electric vehicles
Tema Archiv | 1993
|Advanced ultralight hybrid-electric vehicles
Kraftfahrwesen | 1993
|