The 5kW Charging System Of Lead-acid Battery

Basing on the analysis of the current status of research on high power lead-acid battery charging system,a 5kW lead-acid battery charging system is designed in this paper.The work includes the following four parts:(1)The overall design scheme of the system is established,the system is composed of two parts:AC-DC and DC-DC.In order to achieve design requirement of the high power factor,the interleaving boost topology is selected for the AC-DC,the power rating to 5kW;In order to achieve design requirement of four groups of independent battery charging,the dual switch forward topology is selected for the DC-DC,a total of four dual switch forward charging modules,the power rating of each charging module to 1.2kW.Interleaving boost PFC circuit and dual switch forward circuit are introduced,and two kinds of circuit characteristics are deduced in detail.(2)The main circuit of interleaving boost is designed,the type of power devices and the type of inductive magnetic core are selected.The chip of UCC28070 is selected as the main control chip of interleaving boost,and it's peripheral circuit is designed.(3)The main circuit of dual switch forward is designed,the type of power devices and the type of transformer are selected.The chip of NCP1252 is selected as the main control chip of dual switch forward,and it's peripheral circuit is designed The control circuit of three stages charging is designed.(4)The charging system prototype is made,interleaving boost PFC,dual switch forward charging circuit and the whole system are tested respectively.Through the experiment testing,when the system outputs the rated power,the power factor is 0.995,the efficiency is 92.1%,and the three stages charging is realized.