ABSTRACT For traction system, when there is a transient high power requirement, such as an acceleration or cold start, the battery can be boosted with UltraCapacitor (UC). The UC shows an extremely high power density. So it is capable of... more
ABSTRACT For traction system, when there is a transient high power requirement, such as an acceleration or cold start, the battery can be boosted with UltraCapacitor (UC). The UC shows an extremely high power density. So it is capable of supplying pulse energy within a short time. While the battery can provide high power, just not high as the same UC's size. Both of UC and battery on board are rechargeable. The kinetic energy won't be wasted but transferred into electric energy and recaptured by the UC or battery. Using the phase shift modulation angle of Dual Active Bridge Isolated Bidirectional Converter, will save the energy and improve the system's efficiency.
—With exceptional features and a long life, the UltraCapacitor (UC), can arguably sustain the battery (main source of energy). It also is a necessary complement in electric cars. This article discusses the management of energy between the... more
—With exceptional features and a long life, the UltraCapacitor (UC), can arguably sustain the battery (main source of energy). It also is a necessary complement in electric cars. This article discusses the management of energy between the various components of an electric vehicle based on a traction machine designed around a Permanent Magnet Synchronous Motor (PMSM). The proposed design uses a DC/DC bidirectional Dual Active Bridge (DAB) with a High Frequency Transformer (HFT), except for the isolation. The HFT allows the adaptation of the voltage of the UC to the DC Bus. The number of UC cells in series will be limited what keeps a high value of equivalent capacity and low Equivalent Series Resistance (ESR). In addition, it facilitates the balancing of the voltages across the different cells. Continuous bus directly connected to the battery can provide continuous power to the PMSM. The UC temporarily stores energy recovered during braking or deceleration for any use covering peaks of power demand during acceleration and starts. Thus, it relieves the battery, extends its life and allows the improvement the overall performance of the electric vehicle.
Electric vehicles have recently attracted research interest. An electric vehicle is composed of two energy sources, such as fuel cells and ultracapacitors, which are employed to provide, respectively, the steady-state and transient power... more
Electric vehicles have recently attracted research interest. An electric vehicle is composed of two energy sources, such as fuel cells and ultracapacitors, which are employed to provide, respectively, the steady-state and transient power demanded by the vehicle. A bidirectional DC-DC converter is needed to interface the ultracapacitor to a DC bus. The pack of ultracapacitor consists of many cells in series and possibly also in parallel. In this regard, this paper introduces a comparative study between two packs of supercapacitors. The first supercapacitor pack is composed of ten cells in series but the second supercapacitor pack is composed of five cells in series and two parallel circuits. Each cell is characterized by 2.5 V and 100 F. A number of practical tests are presented.
