화학공학소재연구정보센터
Applied Energy, Vol.205, 244-259, 2017
Stability enhancement of the motor drive DC input voltage of an electric vehicle using on-board hybrid energy storage systems
There are several advantages in keeping motor drive DC input voltage stable around its nominal value especially when it comes to minimize losses. This paper deals with the stability enhancement of the motor drive DC input voltage of an electric vehicle with on-board hybrid energy storage system. On one hand, the natural voltage variation at the output battery pack can be avoided by using a DC/DC converter connected between the battery and the motor drive. On the other hand, the incorporation of supercapacitors in small urban electric vehicles enables handling power peaks thus reducing the battery current root-mean-square value, which in turn increases the battery lifetime. Several topologies can be considered for the coupling of supercapacitors with the vehicle energy system. In this paper, three topologies are studied: battery-only, direct hybrid coupling, and active parallel hybrid coupling of batteries and supercapacitors. A reduced-scale power level hardware-in-the-loop test bench has been built to analyze the performance of the hybrid topologies under the ARTEMIS driving cycle. Experimental results show the effectiveness of the active parallel configuration controlled by an improved energy management strategy that dynamically regulates the supercapacitors state-of-charge. The analysis performed demonstrates that the use of this configuration coupled with an improved management strategy can increase the power transferred by 80% compared with a battery-only configuration, and by 40% compared with direct hybrid coupling or active parallel coupling configuration with a traditional management strategy, keeping the voltage stability of the DC Link.