Antor
Member level 2
Hello,
I'm trying to build a 3phase-3phase direct converter (Explains my schematics). I'm testing IGBT stage with DC source. Circuit is now just triggering IGBT named SAAF.
Cutting to the chase, I'm triggering only 1 IGBT and chopping a DC for now. I'm sure there will be negative undershoot if I trigger SAAR negative path IGBT too.
There are 3 problems;
1- Overshoot
2- Very bad transient
3- A weird slope after turn-on.
Here is main schematic and its's chield
![MainSchematic.JPG MainSchematic.JPG](https://www.edaboard.com/data/attachments/85/85917-83dff5151b23ffaf31db69e72e180329.jpg)
![MainSchematic2.JPG MainSchematic2.JPG](https://www.edaboard.com/data/attachments/85/85918-13aee92ed2a6dc7ab86b29bb3b30d30f.jpg)
These are the PCB with top and bottom layers
![PCB2.JPG PCB2.JPG](https://www.edaboard.com/data/attachments/85/85920-7e5db12f64a1b460c95958f2f9c2164f.jpg)
![PCB.JPG PCB.JPG](https://www.edaboard.com/data/attachments/85/85919-35d6286f14f4f969a5741ea34bb4a9c8.jpg)
Signal triggering the IGBT driver (HCPL3140) is generated by signal generator. 5V %50 duty cycle @1KHz
![IMG_20190914_203538.jpg IMG_20190914_203538.jpg](https://www.edaboard.com/data/attachments/85/85921-52bcd8cdfee6318f226a35ee0c9c2384.jpg)
Load is a rheostat (around 10ohms, may varry)
Yellow : Output of the IGBT, Blue : Signal triggering IGBT (HCPL3140 output)
DC source of the IGBT 1A/24.2V, Output have an overshoot and a weird slope during on cycle. PWM signal is not in a good condition also.
![003- 1A 24.2V.jpg 003- 1A 24.2V.jpg](https://www.edaboard.com/data/attachments/85/85922-b117598d2ce70bc464a29849b008ff8e.jpg)
DC source of the IGBT 1.24A/30V, Output have an overshoot and a weird slope during on cycle. PWM signal slightly better.
![005- 1.24A 30V.jpg 005- 1.24A 30V.jpg](https://www.edaboard.com/data/attachments/85/85923-f337292bd56a75a95ee0464c1c36edd0.jpg)
DC source of the IGBT 1.33A/31.7V, Output have an overshoot and the weird slope is gone.
![001- 1.33A 31.7V.jpg 001- 1.33A 31.7V.jpg](https://www.edaboard.com/data/attachments/85/85925-ffd0ca259347a7f1f453993eb9d835c9.jpg)
Close shots of overshoot and transient state of turn off
![IMG_20190914_203607.jpg IMG_20190914_203607.jpg](https://www.edaboard.com/data/attachments/85/85926-395c96c6a345610ff0c71cf1ffee962c.jpg)
![IMG_20190914_203713.jpg IMG_20190914_203713.jpg](https://www.edaboard.com/data/attachments/85/85927-f3bf87ecaac1896339bac1455c262057.jpg)
Workspace
![IMG-20190914-WA0049.jpg IMG-20190914-WA0049.jpg](https://www.edaboard.com/data/attachments/85/85928-16206cda3f0939b7578bb6deaa87430a.jpg)
How can I condition the output ?
I'm trying to build a 3phase-3phase direct converter (Explains my schematics). I'm testing IGBT stage with DC source. Circuit is now just triggering IGBT named SAAF.
Cutting to the chase, I'm triggering only 1 IGBT and chopping a DC for now. I'm sure there will be negative undershoot if I trigger SAAR negative path IGBT too.
There are 3 problems;
1- Overshoot
2- Very bad transient
3- A weird slope after turn-on.
Here is main schematic and its's chield
![MainSchematic.JPG MainSchematic.JPG](https://www.edaboard.com/data/attachments/85/85917-83dff5151b23ffaf31db69e72e180329.jpg)
![MainSchematic2.JPG MainSchematic2.JPG](https://www.edaboard.com/data/attachments/85/85918-13aee92ed2a6dc7ab86b29bb3b30d30f.jpg)
These are the PCB with top and bottom layers
![PCB2.JPG PCB2.JPG](https://www.edaboard.com/data/attachments/85/85920-7e5db12f64a1b460c95958f2f9c2164f.jpg)
![PCB.JPG PCB.JPG](https://www.edaboard.com/data/attachments/85/85919-35d6286f14f4f969a5741ea34bb4a9c8.jpg)
Signal triggering the IGBT driver (HCPL3140) is generated by signal generator. 5V %50 duty cycle @1KHz
![IMG_20190914_203538.jpg IMG_20190914_203538.jpg](https://www.edaboard.com/data/attachments/85/85921-52bcd8cdfee6318f226a35ee0c9c2384.jpg)
Load is a rheostat (around 10ohms, may varry)
Yellow : Output of the IGBT, Blue : Signal triggering IGBT (HCPL3140 output)
DC source of the IGBT 1A/24.2V, Output have an overshoot and a weird slope during on cycle. PWM signal is not in a good condition also.
![003- 1A 24.2V.jpg 003- 1A 24.2V.jpg](https://www.edaboard.com/data/attachments/85/85922-b117598d2ce70bc464a29849b008ff8e.jpg)
DC source of the IGBT 1.24A/30V, Output have an overshoot and a weird slope during on cycle. PWM signal slightly better.
![005- 1.24A 30V.jpg 005- 1.24A 30V.jpg](https://www.edaboard.com/data/attachments/85/85923-f337292bd56a75a95ee0464c1c36edd0.jpg)
DC source of the IGBT 1.33A/31.7V, Output have an overshoot and the weird slope is gone.
![001- 1.33A 31.7V.jpg 001- 1.33A 31.7V.jpg](https://www.edaboard.com/data/attachments/85/85925-ffd0ca259347a7f1f453993eb9d835c9.jpg)
Close shots of overshoot and transient state of turn off
![IMG_20190914_203607.jpg IMG_20190914_203607.jpg](https://www.edaboard.com/data/attachments/85/85926-395c96c6a345610ff0c71cf1ffee962c.jpg)
![IMG_20190914_203713.jpg IMG_20190914_203713.jpg](https://www.edaboard.com/data/attachments/85/85927-f3bf87ecaac1896339bac1455c262057.jpg)
Workspace
![IMG-20190914-WA0049.jpg IMG-20190914-WA0049.jpg](https://www.edaboard.com/data/attachments/85/85928-16206cda3f0939b7578bb6deaa87430a.jpg)
How can I condition the output ?