AbstractsEngineering

The modeling, simulation and implementation of a range extender for an existingtruck are presented in this document. The objective of this thesis is to re-engineer anexisting electric truck into a series hybrid electric vehicle through a range extender. ALiFePO4 (Li-Ion) battery pack powered electric vehicle is used as a platform toimplement a range extender using an advanced control strategy.A range extended electric vehicle has been simulated using series hybrid electricvehicle architecture to size the range extender by studying the behavior of the systemunder different drive cycles. To determine the size of the range extender, a specific drivecycle in which the vehicle is considered to be cruising at 65 Mph was selected to studythe operation of the range extended electric vehicle. By analyzing the results of thesimulations it has been concluded that a 30 kW engine and generator set is an appropriatesize of the range extender to design a range extended electric vehicle. The range extenderwas designed, simulated and tested at a bench before it was implemented on a vehicle. A30 kW range extender was developed by mechanically coupling a 40 hp V-twinhorizontal shaft gasoline engine with a 30 kW permanent magnet generator from one ofthe electrical machines in the transmission of 2004 Toyota Prius. A range extendedelectric vehicle control algorithm was developed to control the operation of the engineand generator set relative to the state of charge (SOC) of the battery pack. The mainobjective of the developed algorithm is to maintain the SOC of the battery pack betweena certain limits predefined by the programmer. It was determined that by maintaining theiiiSOC of the battery pack in between 60% to 80% the targeted distance of 100 miles wasachieved with 2 gallons of the gasoline.A novel power converter was developed to convert three phase AC output of thegenerator into an appropriate DC voltage to charge the battery pack. The developedpower converter consists of a three phase diode rectifier electrically coupled with a threelegged interleaved buck converter. This power converter was tested on different electricalloads before implementing on the range extender.The main objective of the developed power converter is to reduce the size of thecomponents. By combining three buck converters in parallel the maximum amount of thecurrent through each buck converter, is reduced to one third of the original current. Aconstant current battery charging algorithm was developed to control power converter.Three PWM signals with 120 deg phase shifted with each other were generated using thecontrol algorithm which will help to reduce the ripple content in the output batterycurrent. With this sequence of the generated PWM the ripple content is reduced by afactor of 6.Additional future work was suggested in this thesis work to increase the reliability ofthe developed range extended electric vehicle.