Research And Design Of New Energy Vehicle Charger

Since 2015,the production and sales volume of new energy vehicles in China have ranked first in the world for 7 consecutive years,and the new energy vehicle industry has achieved rapid development.With the development of the new energy vehicle industry,core technologies of new energy vehicles such as on-board chargers have become the research hotspot of the industry,and a variety of different charging voltage ranges and complex charging algorithms have been formed in the market.Therefore,if the charger module can have efficient output voltage in a wide range,it will have significant cost and economic benefits.Based on this,this paper focuses on designing an on-board charger that can achieve a wide output voltage range to meet the requirements of different charging voltage ranges.First of all,this paper introduces the two-level topologies used in vehicle charger,emphatically analyzes several common topologies and their characteristics.Finally,in order to make the system have a low current ripple,the front stage AC-DC part uses the two-phase staggered parallel Boost PFC.In terms of control algorithm,in order to reduce the operation load of the digital control chip,this paper uses the duty ratio predictive control algorithm.LLC resonant converter with variable structure rectifier is used in the post-stage DC-DC part to achieve a wide output voltage range within a fixed frequency range by switching different modes.After theoretical calculation and simulation verification of the above design,the prototype designed in this paper was tested in practice.The full load power of the prototype was 3.3KW,the full load efficiency reached 95%,and the output voltage range was adjusted from 48 VVDC to 400 VDC,achieving the design goal.