Abstract

International audience; This paper presents a study which follows the present trend in the field of electric (or hybrid) vehicles E(H)V, having in mind that the major drawback of these last ones is the autonomy problem. Thus, by using a hybrid energy source (formed by ultracapacitors and battery) and with a proper current control (of polynomial type) one can get a good energy management which will increase the lifetime of the battery. Through numerical simulations and tests at reduced scale, the authors present a successfully energy management on board of a hybrid vehicle.

Abstract

International audience; This study deals with the dynamic and thermal behaviors of supercapacitors. Characterization is performed using the Electrochemical Impedance Spectroscopy (EIS) method to determine by experiment the supercapacitor's series resistance (ESR) and capacitance according to the frequency. The study deals also the particular case of the supercapacitor's spectra and the thermal shock. Finally, life test at constant temperature and the impact of the vibration on the supercapacitor's parameters are illustrated.

Abstract

International audience; This paper deals with an energy management improvement based on frequency sharing approach for an electric vehicle. In order to satisfy the traction/propulsion system requirement, the Fuel cell (FC) system is assisted by lithium-ion batteries and Supercapacitors (SC). Bidirectional Buck Boost converters link the batteries and Supercapacitors to the DC-Bus. The FC stack is connected to the DC-Bus by an interleaved Boost DC-DC converter. The traction/propulsion motor is a permanent magnet synchronous motor (PMSM) coupled to a DC motor in order to emulate the vehicle's load and energy requirements during the driven cycle. The DC-Bus feeds the permanent magnet synchronous motor via a bidirectional DC-AC converter. The contribution of this study involves EV's energy effort sharing between Supercapacitors, Fuel cells and Lithium-ion batteries, taking into account the dynamic responses and electrical performances of each energy sources. The effectiveness of the control is verified through simulations performed on Matlab/Simulink software.

Abstract

This paper presents a study of the combined influence of battery models and sizing strategy for hybrid and battery-based electric vehicles. In particular, the aim is to find the number of battery (and supercapacitor) cells to propel a light vehicle to run two different standard driving cycles. Three equivalent circuit models are considered to simulate the battery electrical performance: linear static, non-linear static and non-linear with first-order dynamics. When dimensioning a battery-based vehicle, less complex models may lead to a solution with more battery cells and higher costs. Despite the same tendency, when a hybrid vehicle is taken into account, the influence of the battery models is dependent on the sizing strategy. In this work, two sizing strategies are evaluated: dynamic programming and filter-based. For the latter, the complexity of the battery model has a clear influence on the result of the sizing problem. On the other hand, a modest influence is observed when a dynamic programming strategy is followed.

Abstract

High energy density storage device exhibiting a reliable lifecycle is needed in the 21st century. Hence, energy storage research is critical for reducing energy consumption. Supercapacitors exhibit such characteristics via interfacial ion electrosorption and fast redox reactions. They are a feasible solution for transportation applications, among others, due to their superb characteristics. In this paper, we provide a background on supercapacitors, review public data on commercially available supercapacitors for performance characteristics, and finally summarize their performance in terms of energy density, equivalent series resistance, and device time consistency. Document type: Article