| With the increasing serious problems of environment and the shortages of fossil energy,the exploitation and utilization of new green energy has aroused general concern.Furthermore,a reliable and stable power supply systems is especially important.However,as an important energy storage device for electric vehicles and UPS uninterruptible power supply,battery still has many problems in its usage,the most serious one is the damage of battery life span caused by undue charging.First of all,through the comparison and analysis,the writer finds out the advantages and disadvantages of traditional charging strategies of lead-acid battery respectively,and then explains the harm of polarization to the battery and provides solutions.Secondly,referring to Mas’ s law,the writer chooses a fast charging strategy which combined negative pulse discharging with multi-phase constant current charging.This strategy can make the battery charge current closer to its acceptable curve and remove the polarization phenomenon effectively,thus increasing the battery charging efficiency and its life span.In order to verify the feasibility of the proposed charging strategy,the designed hardware includes three-phase transformers,filter circuits,three-phase PWM rectifier circuits,bidirectional DC-DC conversion circuits,DSP control circuits,voltage and current sampling circuits,and switch tube drive circuits and so on.DSP control program was designed in the CCS6.0 integrated development software,each of its sub-program module can achieve the real-time monitoring of the battery charging.Finally,the feasibility of the proposed strategy is verified by simulations and experiments.This paper simulates the fast charging system in MATLAB/Simulink software and builds an experimental platform for it.The intelligent rapid charge voltage and current waveforms of the battery is both observed in the software and platform oscilloscope,which verified the feasibility of the charging control strategy. |
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