Award Date


Degree Type


Degree Name

Master of Science (MS)


Electrical Engineering

First Committee Member

Yahia Baghzouz

Number of Pages



The concept and application of ultracapacitors for electric load leveling and regenerative braking is presented. Proposed sizing of an ultracapacitor system is presented and discussed based on the available energy and the nominal operating voltage from a hybrid electric vehicle transit bus; A control scheme is required to effectively control the charge and discharge of the ultracapacitor system. This system is required to provide for electric load leveling, effective control and maximization of the regenerative-braking system. In order to optimally control the ultracapacitor system a DC/DC converter is required. Alternatively, direct connection of the ultracapacitor system across the battery bank does not allow for control of energy flow but does assist the battery system by altering the charge and discharge rate thereby reducing the stress on the battery system. Both connections of the ultracapacitor system were investigated. System integration using optimal power dispatch from the battery packs and generator was investigated with the aid of PSPICE and the Advanced Vehicle Simulator (ADVISOR) developed by the National Renewable Energy Laboratory (NREL).


Braking; Electric; Hybrid; Regenerative; Ultracapacitors; Vehicle

Controlled Subject

Electrical engineering; Automobiles--Design and construction

File Format


File Size

2222.08 KB

Degree Grantor

University of Nevada, Las Vegas




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