Modeling the Electrically Assisted Variable Speed (EAVS) Supercharger Eaton Corporation Vehicle Group Brian Smith Brandon Biller
Overview of EAVS Technology 2
EAVS System Development at Eaton Hardware refinement Gearbox design emotor selection Supercharger selection Hardware validation Bench Testing Flowbench testing Performance mapping Desig n Modelin g Vehicle calibration Data collection Emission regulation assessment Concept demonstration Testing System matching Engine/ vehicle performance predictions Controls development Architecture trade studies 3
Modeling Motivations Application: 1.4L Base Engine, 23 bar BMEP, 95 kw/l 48V EAVS boosting/ mild hybrid system 1750 kg vehicle Evaluate the performance, fuel efficiency, drivability value proposition Study state control strategies for EAVS operating modes Study electrical demand & develop energy management strategy Correlate to test vehicle & guide future improvements 4
Engine Model Construction Show side by side of FRM baseline and revised versions Started with 1.4L turbocharged fast running model (FRM) Nearest match to baseline I4 Ecotec Cruze Eco Engine 5
FRM Model Conversation Removed turbocharger Show side by side of FRM baseline and revised versions Removed turbocharger 6
FRM Model Conversation Incorporate supercharger and planetary system Show side by side of FRM baseline and revised versions Steady state modeling - expand torque curve 7
FRM Model Conversation 8
FRM Model Conversation Incorporate operating mode controller Improved transient controls Validated electric motor model Validated battery model 9
FRM Model Conversation Increased mass to 1750kg 10
Event Manager Robust Method for Supervisory State Control Event Manager Template provides supervisory control of the system to determine operating mode Operating Mode Event Manager Throttle Controller Electric Machine Controller IF-THEN-ELSE Templates govern the lower level controllers based on the operating mode request from the Event Manager Operating Modes 1. Stopped, Engine Off 2. Starting Engine 3. Idle 4. NA Engine Operation 5. Boosted Engine Operation 6. Generator 7. Torque Assist 8. Brake Regeneration 11
Simulation Value Study Emissions Cycles Understand most influential engine operating points Operating mode breakdown over emission cycles Balance electrical system state-of-charge Maximizing energy recuperation 12
Vehicle Fuel Economy Results Fuel Economy FTP75 US06 HWFET Simulation (mpg) 42.4 31.1 53.4 Vehicle Dyno Test* (mpg) 36.9** 30.1 53.4 Percent Error (%) 13% 3.2% 0% Simulation (% SOC) Vehicle Dyno Test (% SOC) Battery State of Charge Initial = 90% 90.4 94.5 91.5 91.0 92.5 87.0 *Standard regulatory emissions cycle testing at qualified 3 rd party **Vehicle start-stop system was not active on all opportunities for engine-off state during actual test a major contributor to higher fuel consumption & discrepancy 13
Benefits of Model Development Powertrain systems architecture approach Influences & sensitivity of sub-system impacts on fuel economy & performance better understood Capture transient effects and hybrid system influences on cycles and real world driving Simulation leads decision making process for hardware & vehicle design changes Value proposition construction and scenario iterations 14
GT-Module Supports Customer Evaluation 15
Conclusions GT-Suite model helps to lead the development of EAVS technology at Eaton Simulation drastically reduces need for hardware iterations Ambiguity of OEM s approaches for electrification can be studied in advance Customer module provides robust method for integration into any engine models 16
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