Hybridization of Supercapacitor and Battery for Fast Charging of Electric Vehicles

Abstract

The number of electric vehicles (EVs) used for both private and public transportation has significantly increased during the previous years. The electrical system now faces enormous power demands, particularly where quick charging is necessary. We developed an innovative change in the existing infrastructure for rapid charging in EV based on super capacitors. This infrastructure will be included with a bank of supercapacitor which are directly supplied through the EV's plug in port and this bank will be used to charge the energy storage system (lithium-ion battery) in electric buses, we concentrate on public transport since they are directly associated with the public, where charging time is the biggest concern. A supercapacitor is a device for storing energy that is frequently subjected to short-duration, high-current charge and discharge cycles. So, here we are using a supercapacitor that charges and discharges in less time. The design of electric vehicle will remain the same, but we are adding a super capacitor bank inside the EV for charging the battery. The super capacitor is supplied from through the off-board charger with the plug-in configuration. The supercapacitor bank is then discharged through a buck converter in order to make the charge suitable for charging the Lithium-ion battery in EV. Since the ability of super capacitor to get charged is very fast and it takes only few seconds to get charged from the charging panel and the vehicle need not be intact with the connector in station for longer period of time and this super capacitor slowly charges the battery through the buck convertor thereby reducing the need of long hours to get charged. In order to increase the efficiency of longevity of battery to remain charged we have also made a little innovation in the EV's motor configuration, when the force given to accelerator is removed the inertia will create a reverse action and motor will try to act as generator which will not happen in usual EV but here we make use of a Traction inverter to trap the generator power to give back to the supercapacitor bank, thereby increasing the efficiency of charging and discharging of the super capacitor bank.