| It's a pervasive problem that bidirectional DC/DC converter(BDC)has a low efficiency when it works in light load,and this paper research on the problem.This paper introduces the interleaving technique and magnetic integration technology to reduce the current ripple,output voltage ripple and improve the response speed of converter.Analysis of the full duty cycle,N-channel interleaved magnetic integrated BDC's Buck work mode,deduced the formulas of equivalent inductance,phase current ripple and total output current ripple,further analysised the losses of each part under the Buck mode,summed up the selecting regular of optimal shedding-phase point in the channel control.Come up with a control strategy of the number of active phases,which aims at raising light load efficiency,by reducing phases based on load the load reduction ratio to remove all loss of unworking phases.Meanwhile,used a rotating phase-shedding scheme for efficieent light-load control,resulting in distribution of the aging effect among the phase instead of a single phase and realizing high efficiency in all load conditions.Obtained the optimum value of the coupled coefficient though the influence of the coupling coefficient of the converter in the control channel,and designed the coupled inductor which suitable for phase shedding.The correctness of interleaving magnetic integration(BDC)coupled coefficient selected and the formula of optimal phase-shedding point,the effectiveness of phase control method are verified by experimental results. |
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