DC-Coupled Extreme Fast Charging for Electric Vehicles Using DAB Converter

Currently, long charging times are a major problem hindering the spread of electric vehicle (EV) technology. This paper develops a DC-coupled bidirectional extreme fast charger (XFC) for EVs with a power range of 1.4 MW, and an output voltage range of 1500 V, the highest charging voltage within the CHAdeMO standard. The dual active bridge (DAB) converter serves as the foundation of the developed XFC's multi-level structure. It has proven feasible to integrate Energy Storage Systems (ESS) with DC renewable energy sources for each level of the converter, eliminating the AC-AC stage from the conventional XFC design and resulting in a smaller load size at a lower cost. The presented XFC is simulated using MATLAB/Simulink. The findings shown that using the constant-current constant-voltage (CCCV) charging method based on two nested PI controllers, the heavy vehicle battery pack with a capacity of 540 kWh could be charged from 20% to 90% state of charge (SOC) in as little as 18 minutes and 40 seconds. A prototype 1 kW bidirectional DAB converter laboratory model with SiC MOSFET switches was created and demonstrated. The outcomes of the practical part were in good agreement with those of the simulation and mathematical analysis