DC Charger Circuit Optimization Design and Fast Charging and Discharging Mechanism Research

With the advent of the era of new energy vehicles, the layout of charging piles is slightly lagging behind, and the charging efficiency of chargers is uneven, which leads to the problems of difficult charging and long charging time of electric vehicles. Therefore, market users put forward higher requirements for the charging efficiency of chargers. This paper first analyzes the circuit design principle and loss of the traditional charger, then designs a zero voltage switch(ZVS) half-bridge three-level DC/DC converter with high charging efficiency, and proposes a multi-stage constant current limiting charging strategy. Finally, through simulation and experimental verification, it is proved that the proposed strategy can strengthen the voltage regulation ability of the charger, and can achieve a stable current sharing state when charging.