An RLL Current Sharing Snubber for Multiple Parallel IGBTs in High Power Applications

Abstract

A resistor–inductor–inductor <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(RLL)</i> snubber is proposed for high-power power electronic devices that use insulated gate bipolar transistors (IGBTs) in parallel. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RLL</i> snubber provides current sharing for parallel IGBTs by utilizing series inductors to decrease the rate of current change in turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> and turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> transients. Compared with other methods, the proposed snubber incorporates only passive components without additional sensors or control circuits, which shows its advantages of simple structure, strong applicability, and easy implementation. In order to further expand its application scope, the topologies of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RLL</i> snubber for multiple IGBTs in parallel are designed and improved. Experimental results of 5 and 6 parallel IGBTs validate the feasibility and effectiveness of the proposed snubber.