不对称半桥变换器直流偏磁抑制与软开关实现  

Suppression of DC bias of magnetizing current and realization of ZVS in asymmetric half bridge converter

作　　者：赵清林[1] 吕健[1] 

机构地区：[1]燕山大学电力电子节能与传动控制河北省重点实验室,河北秦皇岛066004

出　　处：《电源技术》2012年第10期1530-1533,共4页Chinese Journal of Power Sources

摘　　要：不对称半桥变换器(AHB)利用变压器自身的漏感和开关管的寄生电容串联谐振,实现了开关管的零电压开通(ZVS),从而降低了损耗,提高了效率。但是其不对称的控制方法使变压器原边电压正负波形不对称,原边电流含有直流成分,容易导致变压器铁心直流磁通累加而饱和。虽然铁芯加气隙后可防止饱和,但又会增加变压器损耗。针对倍流整流式不对称半桥变换器直流偏磁的产生原因及实现软开关的开关工作过程做了理论分析,在此基础上,设计并制作了实验样机。通过对实验结果的分析,验证了倍流整流式不对称半桥变换器采用副边串联隔直电容的方法可以有效抑制变压器直流偏磁,并且实现了软开关。The asymmetrical half bridge（AHB） converter has a zero voltage switching（ZVS） capability.This type of converter takes advantage of resonance oscillation between the leakage inductance which is attached to transformer and parasitic capacitance inside the power mosfets.This characteristic reduces loss during the switching process,and improves the efficiency of the converter.But,there are asymmetrical voltage waveforms in the primary side of the transformer for the asymmetrical control method.Hence,the current of primary winding contains DC off-set.Magnetic saturation can be solved by cut-off air gap on the ferrite core which is caused by DC magnetic flux accumulation of inductor＇s current,but it will increase power loss of transformer.So,theoretical analysis about the occurrence of dc bias of magnetizing current and process of ZVS specifically for AHB convertor with current double rectifier was made in this paper.According to the theory analysis,an experimental prototype was designed and built.Finally,the analysis was verified by experimental results.

关 键 词：软开关 直流偏置 激磁电流 倍流整流 

分 类 号：TM46[电气工程—电器]