<p>Ever-increasing need for freight transportation and mounting environmental concerns call for a cleaner and more efficient energy source. Hybrid electric vehicles have shown potential to reduce both petroleum usage as well as harmful emissions. In this thesis, a newly developed series hybrid electric powertrain by a small start-up company is studied on a route between Florence, Kentucky and Cambridge, Ohio hubs to evaluate potential fuel savings due to hybridization.</p> <p> </p> <p>An experimental testing protocol to calculate fuel economy has been developed and the real-world fuel economy of this hybrid electric powertrain is calculated. A vehicle simulation model representing the experimental powertrain is created in Autonomie and this vehicle model is simulated on three distinct drive cycles obtained from experimental testing phase. These results are compared with a conventional class 8 truck to evaluate fuel savings. The simulation analysis indicates that fuel economy of hybrid is better on only one of the three drive cycles under consideration. Further, it is determined that the existing powertrain does not meet the gradeability criterion. To remedy this, a series electric hybrid powertrain with different compo-</p> <p>nent sizes is then modeled and simulated on the same drive cycles. The modified powertrain is found to result in fuel economy improvement on all three drive cycles considered while also meeting the gradeability requirement. The effect of drive cycle on fuel economy of a hybrid powertrain is also studied in this thesis.</p><br>

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xiii, 112 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 107-112).

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 97-99). Also available on the World Wide Web.

This research is focused on designing a new generation of CAD tools that could help a ”hybrid vehicle” designer with the design process to come up with better vehicle configurations. The conventional design process for any type of hybrid-electric vehicle would start from the vehicle performance criteria and continue by applying them to the physical models of different components of the vehicle. The final result would be strict and precise characteristics of all components in the vehicle; this scenario gives only one option for the desired vehicle. A new perspective is introduced in developing a new methodology in the art of design. This new method enables the designer to see a wider picture of what he is designing and have access to all his options and capabilities. The method is designed to help the designer ask the right questions about his design options, intelligently guide him through the design process by squeezing the space of solutions and take him to the final designed product. The new methodology is implemented in this research with the following capabilities: 1. The proposed tool allows the designer to choose any arbitrary set of variable to be known and leave the rest as the ones to be solved for; either they are vehicle component characteristic variables or performance measures. This provides a great amount of flexibility and success in designing a vehicle from any available information about it. 2. Instead of starting from single values, the new tool can work with a range of possible values for the known variables and suggest range of feasible values for the unknown variables. This provides the capability of refining the design even further and performing sensitivity analysis. 3. The proposed tool is a package that offers both design and simulation capabilities. It includes analytical performance simulation as well as simulation with arbitrary drive cycles and engine controllers. 4. Capability of 1D, 2D and 3D representation of any arbitrary set of design variables in the solution space. The idea is implemented in a pilot version software package for vehicle design.

System level parametric design of hybrid electric vehicles involves estimation of the power ratings as well as the values of certain parameters of the components, given the values of the performance parameters. The design is based on certain mathematical equations or ‘design rules’, which relate the component parameters and the performance parameters. The flow of the design algorithm is uni-directional and fixed, and cannot be altered. This thesis proposes a new method for such parametric design, called omni- directional design, which does not have a fixed sequence like the conventional design, but can start with any parameters of the designer’s choice. The designer is also able to specify the input parameters over a range, instead of a point (one, fixed value) input. Scenarios having a point input, but values of an output which can vary over a range for the point input, can also be studied.

Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Dr. A. P. Meliopoulos; Committee Member: Dr. David Taylor; Committee Member: Dr. Ronald Harley; Committee Member: Dr. Shijie Deng. Part of the SMARTech Electronic Thesis and Dissertation Collection.

No description available.

This thesis investigates modeling and simulation of hybrid electric vehicles with particular emphasis on transient modeling and real-time simulation. Three different computer models, i.e. a steady state model, a fully-detailed transient model and a reduced-intensity transient model, are developed for a hybrid drive-train in this study. The steady-state model, which has low computational intensity, is used to determine the optimal battery size and chemistry for a plug-in hybrid drive-train. Simulation results using the developed steady state model show the merits of NiMH and Li-ion battery technologies. Based on the obtained results and the reducing cost of Li-ion batteries, this battery chemistry is used throughout this research. A fully-detailed transient model is developed to simulate the vehicle behaviour under different driving conditions. This model includes the dynamics of the power train components such as the engine, the power-electronic converters and vehicle controllers of all levels. The developed transient model produces an accurate representation of the drive-train including the switching behaviour of the power electronic converters. A reduced-intensity transient model (also referred to as a dynamic average model) is developed for real-time hardware-in-loop simulation of the vehicle. By reducing the computational demand of the detailed transient model using averaging techniques, the reduced-intensity model is implemented on a real-time simulator and is interfaced to an external subsystem such as an actual battery. The setup can be used to test existing and emerging battery technologies, which may not have an accurate mathematical model. Extensive tests are performed to verify the accuracy and validity of the results obtained from the developed hardware-in-loop simulation setup.

This thesis investigates modeling and simulation of hybrid electric vehicles with particular emphasis on transient modeling and real-time simulation. Three different computer models, i.e. a steady state model, a fully-detailed transient model and a reduced-intensity transient model, are developed for a hybrid drive-train in this study. The steady-state model, which has low computational intensity, is used to determine the optimal battery size and chemistry for a plug-in hybrid drive-train. Simulation results using the developed steady state model show the merits of NiMH and Li-ion battery technologies. Based on the obtained results and the reducing cost of Li-ion batteries, this battery chemistry is used throughout this research. A fully-detailed transient model is developed to simulate the vehicle behaviour under different driving conditions. This model includes the dynamics of the power train components such as the engine, the power-electronic converters and vehicle controllers of all levels. The developed transient model produces an accurate representation of the drive-train including the switching behaviour of the power electronic converters. A reduced-intensity transient model (also referred to as a dynamic average model) is developed for real-time hardware-in-loop simulation of the vehicle. By reducing the computational demand of the detailed transient model using averaging techniques, the reduced-intensity model is implemented on a real-time simulator and is interfaced to an external subsystem such as an actual battery. The setup can be used to test existing and emerging battery technologies, which may not have an accurate mathematical model. Extensive tests are performed to verify the accuracy and validity of the results obtained from the developed hardware-in-loop simulation setup.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.