Implementation of power electronic energy storage unit designed for Chalmers ECO-marathon hybrid car

Abstract

The general scope of this master thesis work is to design, construct and evaluate the electric storage unit and parts of the electric drive train for the series hybrid car Smarter. Smarter was designed by master students at Chalmers, and would be participating in the Shell ECO marathon competition in 2009. A supercapacitor (LIC) was designed and constructed by combining individual Lithium- Ion supercapacitor cells. The LIC was evaluated and compared to a commercially available supercapacitor (Maxwell EDLC), to decide which one to use in the SMARTER car. Two power electronic converters, along with converter control methods, were evaluated with regards to design and performance. This thesis work also covered the installment of the chosen equipment in the vehicle, therefore installment issues such as cabling and connection points also needed to be considered. Both supercapacitors that were tested were found to fulfill performance requirements, but with the LIC a significant reduction in weight was achieved, mainly due to its acrylic glass housing. Both converters were found to be suitable, one being better in one aspect, the other better in another, so both were prepared to be installed in the car and both were actually used during the race runs. Unfortunately due to mechanical issues SMARTER was not able to complete any of the three race runs it was supposed to. Therefore it is difficult to draw any detailed conclusions about the performance of the electrical storage and power converter design, but the design and the entire hybrid drive train was operational and functioned as intended.