MODELING AND ANALYSIS OF ENERGY CONSUMPTION IN CHEVROLET VOLT GEN II HYBRID ELECTRIC VEHICLE

A high fidelity vehicle model is important to predict energy consumption of vehicle and to implement control strategies for further improvement in performance of vehicle. The work in this thesis, describes modeling procedure for developing a high fidelity model of plug in hybrid electric vehicle (PHEV) Chevrolet Volt Gen II using parameters provided by General Motors, is as a part of Advanced Research Projects Agency Energy (ARPA-E) group\u27s NEXT-Generation Energy Technologies for Connected and Automated On-Road Vehicles (NEXTCAR)\u27\u27 project. Each powertrain component , namely; internal combustion engine (ICE), motor generators, battery, traction power inverter module (TPIM) and drive unit, have been developed using high fidelity parameters in MATLAB/ Simulink. In addition to major powertrain components development process, several energy affecting components/ conditions were modeled. To enhance accuracy of energy consumption prediction of battery, a regression fit drive unit auxiliary pump model, dependent on vehicle speed, axle torque and operating mode, was developed using experimental Argonne National Laboratory (ANL) test data. Further improvement in engine fuel energy prediction was improved by incorporating rule based fuel penalties (catalyst light-off , cold-start and cranking) that depends on three way catalyst (TWC) and engine coolant temperatures. In-vehicle testing was carried out to accomplish this task. To predict engine coolant temperature, a lumped coolant model was developed which will be necessary for predicting cold-start fuel penalty. Catalyst thermal model was develop to predict TWC temperature. This thesis walks through validation process of each subsystem developed with experimental ANL test data and, validated components were integrated to develop a Chevy Volt Gen II model. The developed model was validated for US06 and Highway Fuel Economy Test (HWFET) drive cycles provided ANL for both charge sustaining (CS) and charge depleting (CD) test cases. The total energy (sum of electrical and fuel energy) of developed model is well with 5 % error compared to ANL test data. Further analysis of engine transient operation, causing transient fuel penalty, has been performed which a map-based engine model is incapable to predict. Using this analysis, an engine transient fuel penalty map was developed which will make a map-based model to mimic as a dynamic engine model. Moreover, mode switch fuel penalties have been analyzed and incorporated in the model