一种低漏感平面变压器

A kind of low leakage inductance planar transformer

变压器的漏感是电磁干扰的主要来源之一,这是因为开关管在高速关断时,在变压器的漏感上产生感应电动势,叠加在变压器绕组的关断电压上,形成关断电压尖峰,这些电压尖峰不但造成电磁干扰,还会使开关管的电压应力增大,重者可能击穿开关管,并增大开关损耗,降低开关电源的效率。本文提出一种分布磁路结构的低漏感平面变压器,其原边绕组的匝数降低为一匝,副边绕组的等效匝数降低为小于一匝,因而漏感显著减小,这种分布磁路结构可以用于低压大电流电源的变压器,其有效性通过Maxwell 3D得到验证。

It＇s necessary to decrease the leakage inductance of transformer because it often produces a large voltage peak as device is turned off, meanwhile the large voltage peak is a source of EMI and produces a large voltage stress and affects the power supply＇s efficiency. This paper proposes a kind of low leakage inductance planar transformer with shunt mag- netic circuit structure, the primary winding number of this structure can be decreased to 1 turn and the equivalent secondary winding can be decreased to less than 1 turn, therefore the leakage inductance can be decreased remarkably, and it can be used to various turns ratio of high frequency transformer expressly in the transformer of low voltage and large current power supply. The shunt magnetic structure is verified with Maxwell 3D.