Master Thesis
LiU x Aurobay: Electrically Assisted Turbocharger: Modelling And Control Strategy
Abstract
A major cause of CO2 emissions today is fossil fuel vehicles, and lowering these emissions is of key importance, resulting in increasing electrification and hybridisation nowadays. Turbochargers have been used for a long time to recycle exhaust gas heat losses to improve engine performance by compressing the intake air. This thesis investigates a turbocharger with an added electric machine, to see if further energy can be recovered from these gasses, as well as how to control this machine for improved transients during acceleration and reduced turbo lag. A complete Simulink model is created of the system, comprised of a variable geometry turbine, compressor, cylinder, electric motor and battery model. This plant model is then evaluated on test cycles, which results in consistently lowered brake-specific fuel consumption and quicker responses at the cost of electric charge. The results show that an electrically assisted turbocharger poses as a feasible option for further improvements in fuel economy and performance during transients for spark ignited engines.
Publication:
Bachelor Thesis
Background
My group work
Main project
The backstory to the thesis came from a concept of electrifying the LiU FS race car. During the 2019 FSUK competition at Silverstone Circuit, I began to evaluate different solutions and came to a conclusion. In order to benefit the team, a way to kick-start the electrification was to pitch the idea of a bachelor thesis, as the team had collaborations with the university. I had the opportunity to discuss ideas for projects with the senior lecturer in charge of bachelor thesis's of our department. As hoped, my idea of an in-hub electrical motor assembly became a desirable project and was added to the list.
Main project
My group work
Main project
The project consisted of an in-hub motor assembly for an all wheel drive race car. As the main project was quite excessive in design areas for only 2-3 students over a short time period, it was divided into two subgroups; main assembly with motor integration and gearbox assembly.
My group work
My group work
My group work
In my group, which worked with the main assembly and motor integration we worked with:
- motor selection and cooling
- upright design
- wheel hub design
- brake system
For these components we designed the majority of the parts. We also carried out different calculations in Matlab and simulations in ANSYS, to ensure a proper and systematic approach to the solution.