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AlanPolChip
Level 1
Level 1
First reply posted First like given First like received

Greetings everyone,

I am somewhat new into the motor control field, and this is my first post in the Infineon forum! Nice to e-meet you everyone!

I've been trying to implement my IPM module for moving a 3-phase induction motor ( IGCM20F60GA ) but I am having a major issue related to potential difference between the 15V /5V DC line and the 300V DC bus.

Reading the documentation and implementation notes, I can comprehend that the power bus and the control bus must be isolated one from each other. But according to application schematics and examples, I don't understand how is the difference in potential managed.

AlanPolChip_0-1701192478414.png

I am fairly new into these kind of high voltages, so I am not very comfortable yet.

I have tried to do an implementation, but failed catastrophically with some *magic smoke*  involved.
About the implementation, my 300VDC bus came from a 230VAC-300VDC (rectified) power source.
And regarding to the control part, it came from a 230VAC-16VDC small cheap AC-DC switching power supply.

Both grounds of the 300VDC and the 16VDC where connected according to example schematics, and that made the mains circuit breaker to jump.
The positive of the 300VDC was connected to the P terminal, and the 16VDC positive was connected to the VDD.
Between the 16VDC and the GND I had a 100nF capacitor, as recommended...

Here is another aplication circuit i've found, "showing" how the grounds are separate from each other, yet they are connected in the same node...

AlanPolChip_1-1701194215023.png

 

So... What am I missing ? 
May anyone throw me some light or recommend to me some documentation or reading I should do?

Many thanks in advance.



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1 Solution
Vicky_S
Moderator
Moderator
Moderator
10 likes received 5 likes given 100 replies posted

Hello, 
please clarify below points,
1. potential difference between the 15V /5V DC line and the 300V DC bus.---could you share the schematic and mark the points between which you are observing an potential.
2. I can comprehend that the power bus and the control bus must be isolated one from each other.--- No in documentation it is suggested "The signal ground and power ground should be as short as possible and connected at only one point by the filter capacitor of the VDD line."

I would like to recommend you to open a case in Infineon mycases where you can share shcematic and layout for the review without hesitation. please let me know if you are facing any issue in creating a case there. 

Best regards,
Vicky S

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2 Replies
Vicky_S
Moderator
Moderator
Moderator
10 likes received 5 likes given 100 replies posted

Hello, 
please clarify below points,
1. potential difference between the 15V /5V DC line and the 300V DC bus.---could you share the schematic and mark the points between which you are observing an potential.
2. I can comprehend that the power bus and the control bus must be isolated one from each other.--- No in documentation it is suggested "The signal ground and power ground should be as short as possible and connected at only one point by the filter capacitor of the VDD line."

I would like to recommend you to open a case in Infineon mycases where you can share shcematic and layout for the review without hesitation. please let me know if you are facing any issue in creating a case there. 

Best regards,
Vicky S

0 Likes
Vicky_S
Moderator
Moderator
Moderator
10 likes received 5 likes given 100 replies posted

Hello,
We are kindly waiting for your reply. 

Best regards,
Vicky S

0 Likes