This paper describes the development of a computer model to model performance of ultracapacitor arrays in hybrid electric vehicles. A Power-Based Model (PBM) was created and the results were compared with data from the University of Idaho's ultracapacitor hybrid Future Truck. The PBM accurately predicts vehicle fuel economy and allows quick simulation speed. This model includes a derived Internal Combustion (IC) engine fuel map with interpolation function and a random capacitance generator for balancing circuit implementation. Experimental data showed that the Future Truck averaged 15.9 mpg operating non-hybrid whereas the PBM predicted 16.8 mpg for a non-hybrid set-up over the same drive cycle, a 5% difference. PBM as shown can accurately predict the vehicle performance including the added benefits from implementing an ultracapacitor array and balancing circuits. Using PBM, it is seen that ultracapacitors are a viable energy storage solution for hybrid electric vehicles.
Keywords: hybrid electric vehicles, HEV, fuel economy, future trucks, ultracapacitors, balancing circuits, engine modelling, alternative propulsion, ultracapacitor array performance, simulation, vehicle performance, energy storage