GM Two-Mode油電混合動力系統模糊控制策略

Abstract

Power-split hybrid electric vehicle (HEV) provides two power paths between the internal combustion engine (ICE) and energy storage system (ESS) through gearing and composing an electrically variable transmision (EVT). EVT allows ICE to opertare independently from vehicle speed all the time. Therefore, the ICE can operate in the efficient region of its characteristic brake specific fuel consumption (BSFC) map. If the most ICE operating points produce more energy than the demanded energy by the driver, the extra energy will be stored in ESS and used later. If the most ICE operating points do not meet the demanded energy, the ESS will add more energy to the wheels through electric machines (EMs). In the second part of this reseach, two-mode power-split General Motors Allison Hybrid System II (GM AHS_II) is constructed. The GM AHS_II powertrain is capable of operating in input-split or compound-split EVT modes as well as four fixed gear configurations. Power-split architecture can advantageously combine traditional series and parallel power paths. Beside dynamic programming (DP), Stochastic dynamic programming (SPD) optimal solutions, or Heuristic rule-base methods, a simple Fuzzy Logic Control (FLC) for IC engine and an intelligent supervisory control strategy are suggested, and ICE speed transition limit are also considered in the third part of this research. This study focuses on input-split and compound-split modes in The GM AHS_II powertrain. FLC with optimal thresholds and transitions have been employed to develop this design problem. Using looking forward control algorithms to implement power-split HEV supervisory control strategy can keep ICE operating points in efficient region, and maintain state of charge (SOC) of ESS in optimal range. FLC strategy helps ICE to operate in higher efficiency region 22.7% and to improve fuel economy 27.8% comparing with conventional vehicle.