Annual Report 2009 - webfiles its vmware

Volvo and Scania AB. An industrial PhD-student from AB Volvo is stationed at thedepartment of Energy and Environment at Chalmers with research focus at stateof-healthmodelling of large-cell Li-ion batteries and battery systems for heavydutyHEVs.Initial battery tests were started in 2009 to enable a first characterization of thebattery degradation process. Participation in post-graduate courses in electrochemistryand a literature survey have been parallel activities, as well as thedevelopment of test methods and a statistical analysis of battery load cycles. Theinitial battery tests will be followed by extensive testing and modelling of specificageing mechanism during 2010.Modelling Aimed at Minimizing EMI in Switched DC/DC Converters UsingActive Gate ControlParticipants: Andreas Karvonen, Torbjörn Thiringer,Sponsors: Vinnova, Volvo Cars, SAAB Microwave Systems, Ericsson AB, SKFIn this project, techniques to reduce the EMI from switched power converters areinvestigated. The main goal is to directly approach the generation of unwantedsignals rather than constructing additional EMI-prevention methods such asadditional shielding and filtering.The goal with the project is to push the technology within the design of voltageconversion units forward using theoretical studies as well as experiments. Themain technical focus lies in understanding component functionality and how tocontrol the switching element in an advantageous way by mathematical modellingof the converter. Other important aspects to be investigated are efficiency,robustness, size and cost. The main technique used is shaping of the switchingwave-form, but simulations methods to predict the EMI-levels of a converter arealso investigated.During the first half of 2009, the focus of the project was to complete the licentiatethesis. A novel MOSFET model was introduced and verified by measurementsand simulations. The model was then used to verify the principle of soft-switchingfor a low-voltage MOSFET. During the second half of 2009, the focus of theproject was aimed at understanding the importance of diode reverse recoveryperformance for conducted emissions for a 15W isolated DC/DC-converter. Initialsimulations and measurements of converters have been performed. In addition tothis, an article was extracted from the licentiate thesis and presented at theInternational Conference on Power Electronics and Drive Systems in Taiwan.Energy efficiency using power electronics for fan and pump applications inbuildingsParticipants: Johan Åström, Torbjörn ThiringerSponsors: Swedish Energy Agency, Göteborg Energi AB, Formas36 |