GRID CONNECTED ACTIVE FRONT END RECTIFIER DUAL ACTIVE BRIDGE FOR EV BATTERY CHARGING

Abstract

Electric vehicles (EVs), which are gaining popularity as a green and effective method of transportation, have significantly accelerated the electrification of transportation in recent years. The effective charging of the electric vehicle battery is one of the main issues facing EV adoption. AC/DC and DC/DC converter-based charging systems have become crucial parts of the EV charging infrastructure as a solution to this problem. In order to minimize charging time, increase charging efficiency, and guarantee the longevity of the EV battery, efficient power conversion in both the AC/DC and DC/DC converters is essential. Therefore, to improve the effectiveness and performance of these converters, cutting-edge power electronics technologies are being used, such as wide-bandgap semiconductors (such as silicon carbide and gallium nitride) and high-frequency switching techniques. This thesis describes the implementation of a three-phase grid-connected electric vehicle (EV) battery charging system made up of two conversion stages: an AC-DC stage with a three-phase Active Front End (AFE) rectifier and a DC-DC stage with a single phase Dual Active Bridge (DAB) converter. Because of its high voltage conversion ratio, power density, and galvanic isolation, the DAB is chosen for the DC-DC stage. The AC DC stage's LCL filter at the input is made to suppress the harmonics in the input current. To obtain the necessary DC link voltage, the active front-end rectifier is under decoupled DQ control. To increase battery voltage and decrease ripples, the Dual Active Bridge (DAB) is controlled in a closed loop using an LC output filter. For various load values, all of the switches achieve zero voltage switching (ZVS), which enables the converter to have reduced switching loss and provides higher efficiency. The system is designed for a 10-kW power rating, and MATLAB/Simulink is used to simulate the system under various load circumstances in order to assess the resilience of the converter and controller.