DESIGN AND ANALYSIS OF ONBOARD BATTERY CHARGING FOR ELECTRIC VEHICLE

Abstract

Electrification of vehicles has become a part of globalisation and modernisation due to the increasing concern for carbon emissions. Global demand for clean fuel energy is increasing rapidly due to fuel scarcity and pollution being important concerns. Consequently, researchers are readily focusing on findings in the electric vehicle (EV) domain. EV is becoming popular in various domains like E-bikes, E-scooters, E-rickshaws, E-cars etc. The ones having lower weight are termed as LEV’s i.e., Light electric vehicles. They account for a significant fraction of overall EV and hence cannot be overlooked. The work in this report deals with the design and analysis of onboard battery charging for electric vehicles with various topologies of DC-DC converters like modified, interleaved, isolated, hybrid etc. which are acting as PFC unit in the charger configuration for better and reliable working of charger thereby reducing total harmonic distortions (THD) within acceptable range as well as improving input current power factor towards unity. In addition to PFC, other DC-DC converters are also used for isolation, and better quality of charging current to be used. In this work, flyback converter is being used due to its simple configuration and excellent isolation properties. Results of interleaved and isolated converters are turned out to be good as compared to other configurations of DC-DC converters. A hybrid configuration is also presented in this report work in which ac supply and solar PV integrated is used for charging in which efficiency of charging is enhanced by use of available solar energy. The unidirectional charging is well elaborated with all the topologies in this work. The basic charging infrastructure along with the enhanced quality of input current is elaborated in this report work. It involves an AC-DC converter, a PFC unit, an isolated converter and battery as a load. According to the construction and working chargers can be discussed in two categories one is onboard charger and other is offboard charger. Control techniques involves classical linear PI controllers as voltage controller and current controllers. These constants are helpful in the closed loop operation of charger circuit. So, this work compiles a complete view of a better converter topology required for the sound working of onboard battery charger.