Suitability of Hybrid Electric Powertrains with Electric Turbocharger

This research investigates the effects of an electric turbocharger in a hybrid electric powertrain. First generic vehicle models are created and run to understand the overall powertrain requirements of torque, power and energy of a performance consumer vehicle. Then a low fidelity baseline model of a conventional vehicle is created in Simulink to serve as a baseline measure. To analyze an electric turbocharger system a high-fidelity model in AMESIM of a 4 cylinder turbocharged engine was modified. This engine model was analyzed using virtual dynamometer tests and a simplified look-up table based controller was developed for the electric motor within the electric turbocharger. Next this engine model was inserted within three different types of hybrid powertrain architectures models in AMESIM. Each hybrid powertrain required a unique supervisory controller which was developed using Stateflow in Simulink. These controller algorithms were imported into AMESIM and the model was simulated over standard drive cycles. Since a very wide variation of electrification level exists within hybrid powertrains the supervisory controllers are calibrated for charge-sustaining simulations. This allows for impartial comparisons across the hybrid architectures. Lastly a track drive cycle was developed to understand electric turbocharger effects under high performance loading conditions Thesis Master of Applied Science (MASc) Turbochargers on internal combustion engines can utilize a portion of waste exhaust energy to pump more air into the cylinder leading to greater power and efficiency. A modern high performance 4-cylinder turbocharged engine is capable of replacing a V6 engine of much higher cylinder displacement. However turbocharged engines suffer from ‘turbo lag’ when the engine cannot immediately produce power. An electric turbocharger can virtually eliminate this ‘turbo lag’ as well as generate electricity from excess energy the turbocharger does not use. Electric turbochargers have been development by researchers and various automotive manufacturers. However the potential effects of such a system within the framework of a hybrid electric powertrain in a consumer vehicle has not been quantified. The objective of this research is to use high fidelity models to investigate the effects of an electric turbocharger system within a hybrid powertrain.