Hello Everybody,
We have a problem with an IGBT-inverter circuit (H-Bridge), and an inductive load.
We have the following load:
R = 0.8 Ohm and L = 80 mH.
The IGBT power module is BSM50GD120DN2
with the driver 2SD106AI.
The input voltage (Uzk) that we usually use is 580V but we made this test with 130V. The maximal current that we have is 25A but this test was made with 2A. The problem remains the same even if you change the operating ranges.
Both IGBT located on the right are controlled by one driver, and the IGBTs located on the left side with another one (see attach file: Picture 1.pdf and the info in Half-Brige Mode with Dead Time (Page 20))
We switch the igbts in the following way: (see attach file: Picture 1.pdf)
The problem is that we get during I, III and V current peaks (see attach file: Picture 2.pdf). We have tested with Snubbers, but the problem doesn't seem to be that (We don't get voltage peaks). We think that the problem is the reverse recovery current from the diode that causes a significant overcurrent by switching. But the current peaks that we see in the Picture 2.pdf appears to be too late to be this effect.
Has anyone any idea what it could be? or a solution for it?
More Details:
The signals' colors from Picture 2.pdf correspond to the colors in the schematic diagram from Picture 1.pdf.
Channel 1 - 2 - 4 -> scale 100V:1V
Channel 3 -> scale 1A:100mV
More Pictures:
scope_screenshots.pdf -> They are the same screenshot but the null position / time scale from channels were changed in order to see and compare the curves.
Once again, we tested Snubbers, we changed the Rg resistor (Gate resitor), but these did not improve the problem.
Thank you very much in advance.
Best regards,
Mauro Riva
We have a problem with an IGBT-inverter circuit (H-Bridge), and an inductive load.
We have the following load:
R = 0.8 Ohm and L = 80 mH.
The IGBT power module is BSM50GD120DN2
with the driver 2SD106AI.
The input voltage (Uzk) that we usually use is 580V but we made this test with 130V. The maximal current that we have is 25A but this test was made with 2A. The problem remains the same even if you change the operating ranges.
Both IGBT located on the right are controlled by one driver, and the IGBTs located on the left side with another one (see attach file: Picture 1.pdf and the info in Half-Brige Mode with Dead Time (Page 20))
We switch the igbts in the following way: (see attach file: Picture 1.pdf)
- I- The upper igbts are on (green color = igbt on). The current goes through the upper left igbt, the load and the upper right diode (freewheeling).
- II-The upper left igbt and the lower right igbt are on, the current goes through these igbts and the inductive load.
- III-The lower igbts are on. The current goes through the lower right igbt and the lower left diode. (freewheeling)
- IV-again II
- V- again I
The problem is that we get during I, III and V current peaks (see attach file: Picture 2.pdf). We have tested with Snubbers, but the problem doesn't seem to be that (We don't get voltage peaks). We think that the problem is the reverse recovery current from the diode that causes a significant overcurrent by switching. But the current peaks that we see in the Picture 2.pdf appears to be too late to be this effect.
Has anyone any idea what it could be? or a solution for it?
More Details:
The signals' colors from Picture 2.pdf correspond to the colors in the schematic diagram from Picture 1.pdf.
Channel 1 - 2 - 4 -> scale 100V:1V
Channel 3 -> scale 1A:100mV
More Pictures:
scope_screenshots.pdf -> They are the same screenshot but the null position / time scale from channels were changed in order to see and compare the curves.
Once again, we tested Snubbers, we changed the Rg resistor (Gate resitor), but these did not improve the problem.
Thank you very much in advance.
Best regards,
Mauro Riva
Attachments
-
412.6 KB Views: 113
-
409.3 KB Views: 82
-
419.2 KB Views: 65