Download 1. Introduction Ultracapacitors are a new technology that allows storing 20 times more energy than conventional electrolytic capacitors [1,2]. Despite this important advance in energy storage, they are still far from being compared with electrochemical batteries. Even Lead-acid batteries can store at least ten times more energy than ultracapacitors. However, they present a lot better performance in specific power than any battery, and can be charged and discharged thousands of times without performance deterioration. These very good characteristics can be used in combination with normal electrochemical batteries, to improve the transient performance of an electric vehicle, and to increase the useful life of the batteries [3-6]. Fast and sudden battery discharge during acceleration, or fast charge during regenerative braking can be avoided with the help of ultracapacitors. Besides, ultracapacitors allow regenerative braking even when the batteries are fully charged. This paper describes the design and implementation of a control and monitoring system specially developed for an auxiliary ultracapacitor bank installed in an electric vehicle. The ultracapacitor has a capacity of 20 Farads, a nominal voltage of 300 Vdc, and a maximum voltage of 330 Vdc. The nominal current is 200 amps, and the maximum current is 400 amps. A Bi-directional DC-DC converter has been implemented for energy transfer between the lead acid battery pack and the ultracapacitor bank.
Home Tips & Tricks Monitoring System for Testing the Performance of an Electric Vehicle Using Ultracapacitors