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Paralleling of IGBTs and diodes of one power module can push power capability

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green_is_now
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re: Paralleling of IGBTs and diodes of one power module can push power capability
green_is_now   9/28/2011 6:53:44 PM
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thanks yurmoma, I missed that. Another advantage is that the current is 1/3 and the Ldv/dt will be 1/9th per leg thus less gate drive disturbance fedback into gate driver circuit. Also the current tail is reduced because this is a function of the % of allowed current per device. It gets progressivly worse as you approuch 100% utilization. Also adding a small cap (added to parasitic cap) if needed to provide additional filtering of local gate drive grounds, relative to star ground. This MUST be done with care or it will make it worse. Can't have any other tracks piggybacking on this reference ground connection to star point. This gets blurred if a ground plane is used and room does not permit sepate ground run. Layout software masks this need and wants to just use any connection anywhere. This must be overridden by using a fake part in series to allow another net name and then short out dummy part at end of layout.

yurmom
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re: Paralleling of IGBTs and diodes of one power module can push power capability
yurmom   8/18/2011 3:06:42 PM
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The extra 0.5 Ohm resistors are in the gate drive circuit, not in series with the power output. They only experience short, low-current pulses each switching cycle. And they are low resistance compared to the resistance already in the gate so I would expect negligable overall efficiency impact.

tomkawal
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re: Paralleling of IGBTs and diodes of one power module can push power capability
tomkawal   8/12/2011 8:37:06 AM
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I have only little experience driving IGBTs, and it is good to find some practical info like that. Good to keep my eyes on power electronics from time to time. The paper is easy to understand and it is sort of excellent educational material.

green_is_now
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re: Paralleling of IGBTs and diodes of one power module can push power capability
green_is_now   8/10/2011 6:28:31 PM
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What is the performance improvement in terms of efficiency when you look at the total losses and the added 0.5 ohm sense resistors?

green_is_now
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re: Paralleling of IGBTs and diodes of one power module can push power capability
green_is_now   8/10/2011 6:09:08 PM
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But no mention of the efficiency when 0.5 ohm resistors are added. How do they compare on efficiency?

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