Electric Vehicle On-Board Fast Charging Through Converter Maximum Switch Utilization

This work deals with a single-phase on-board fast charger for electric vehicles (EVs). One of the key parameters to restrict the on-board fast charging is the converter power density. Almost all the existing single-stage and two-stage converter topologies in discontinuous conduction mode are limited to slow charging due to high current stress. Further, these converters, regardless of conduction modes, experience high voltage stress across semiconductor switches due to the interaction between filter and circuit inductances that limit their EV charging rate. To overcome these challenges, in this article, a new concept of utilizing the converter semiconductor switch capacity to facilitate fast charging is proposed. It is demonstrated that by using the converter switch rating at its maximum capacity, the range of power drawn from the input can be extended. To achieve the aforementioned objective, a two-stage configuration based on bridgeless switched inductor (BLSI) Cuk converter is proposed to achieve EV fast charging. The performance of the proposed concept is validated through MATLAB/ Simulink-based simulation study and proof-of-concept with a scaled-down laboratory prototype. It is shown that the proposed concept along with the BLSI Cuk converter can charge EV battery upto three times faster than conventional buck-boost converter-based single-stage and two-stage chargers.