Design, Simulation and Testing of an Electric Utility Vehicle

Transportation is crucial to the global economy but the widespread dependence on fossil fuels has led to problems with excessive greenhouse gas (GHG) emissions. This carbon footprint is associated with climate change and hence, renewable sources or low carbon sources for energy are being sought. There has been a continuous shift over the past decade from internal combustion engine (ICE) vehicles to electric vehicles (EV). Even though more EVs are seen on the road now, transportation and mechanization in the agricultural industry has not seen the same growth. Battery electric utility vehicles hold much potential in terms of providing solutions for mechanization and transportation in developing countries. This can help boost productivity and in turn address the food supply challenge. This thesis is focused on filling this gap and creating a better understanding of the viability of using electric utility vehicles. To accomplish this, an existing Purdue Utility Project (PUP) vehicle was retrofitted with an electric driveline. Two data acquisition (DAQ) systems were developed to record the individual battery voltages, GPS data, and motor signals such as motor speed, current and system voltage. Flat-terrain, hill and range tests were performed for different payload conditions: 0, 1000 and 2000 lb. Simultaneously, a backward facing simulation model was developed to establish a baseline for future electric PUP (ePUP) design and powertrain analysis. The simulated data was compared to the test data for validation purposes. It was found that the model performs with good accuracy for flat ground tests but was predicting the current draw insufficiently for hill tests. The limitations of the model were identified and a comparison of the DAQ measured voltage with the CAN-BUS system voltage revealed superior tracking with less than 5% error. The ePUP maximum speed can vary between 21-28 kmph and the range varies from 11-25 km depending on the payload. It was concluded that the ePUP is a highly viable replacement for ICE utility vehicles. This argument can be strengthened if renewable sources of energy are used to power the ePUP. The model developed in this study allows user flexibility to compare battery technologies and motor performance for future ePUP design