IGBT發(fā)熱,怎么辦

IGBT發(fā)熱,怎么辦
50Hz正弦波逆變器,開關頻率20k,死區(qū)3u,在開關切換的時候,總是有個短路電流流過兩管子,電流峰值80~100A,持續(xù)時間200u.請教高手怎么解決,謝謝

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shilin

LV.1

2004-03-14 12:56

搞錯了
對不起,搞錯了,持續(xù)時間200ns

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pispwm

LV.6

2004-03-15 08:59

@shilin

搞錯了對不起,搞錯了,持續(xù)時間200ns

有圖嗎?
好分析

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wolong

LV.2

2004-03-17 01:41

@shilin

搞錯了對不起,搞錯了,持續(xù)時間200ns

Increase the dead time
Increase the deat time to 5u and check if the short circuit current goes away. If so, it might be your FETs/IGBTs not totally off. And also, double check the PWM pulse sequence between top and bottom switch.

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求學者

LV.4

2004-03-17 09:07

功率很小嗎?怎么這么高的頻率?
?

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shilin

LV.1

2004-03-18 22:41

@wolong

IncreasethedeadtimeIncreasethedeattimeto5uandcheckiftheshortcircuitcurrentgoesaway.Ifso,itmightbeyourFETs/IGBTsnottotallyoff.Andalso,doublecheckthePWMpulsesequencebetweentopandbottomswitch.

懷疑二極管的恢復問題
我有點懷疑是續(xù)流二極管反向恢復帶來的,我測到在正負對稱的時候,就不會有電流.而在不對稱的時候,二極管還處于續(xù)流狀態(tài),對方IGBT導通的時候肯定出現.但不知怎樣解決.

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wolong

LV.2

2004-03-19 00:24

@shilin

懷疑二極管的恢復問題我有點懷疑是續(xù)流二極管反向恢復帶來的,我測到在正負對稱的時候,就不會有電流.而在不對稱的時候,二極管還處于續(xù)流狀態(tài),對方IGBT導通的時候肯定出現.但不知怎樣解決.

UF DIODE?
Check the datasheet of the diode you are using, is it UF diode if you can't use schottkey?

It's difficult to know what really happened without seeing the schematics and the waveforms. But you can definitely check the current on the diodes and IGBTs, find out what happened.

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