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IGBT Forum Discussions

Sriram_07
Level 2
10 likes given 10 replies posted 5 questions asked
Level 2

Hello, 

We are using FS200R07PE4 igbt module for EV motor controller application. While testing the igbt module it suddenly stopped working . DC terminals were short and V phase was shorted with the DC terminals.  the module was powered by a regulated dc power supply . The current was limited to 7 A and the voltage applied was 120 V. We were testing the motor controller with the motor when the failure happened. Can you help us figure out what happened.

Thank you

1.jpg

 

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1 Solution
BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

I can see a lot of noise in the waveform (output terminals). This might be due to a setup issue or design issue. Repeat the above test by placing a low capacitance value across the Input terminals.

BandaruAkhil_0-1668424704095.png

 

Best Regards,

Akhil Kumar.

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BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

Thanks for posting on the Infineon Community page.

Correct me If my understanding was wrong.

Test Condition:  120 VDC and the current limit of 7 A with RPS were applied to the DC terminals of the inverter and outputs are connected to the motor.

The behavior observed:  Direct short between the DC terminals and short between V phase to DC terminals.

Please answer the below questions 

1) Is there any waveform captured during testing? If yes, please share the waveform.

2) Whether can you see the above behavior repeatedly or randomly?

3) What about Gate- Emitter pins. Is there any direct short?

4) Whether the two IGBTs in the V phase are shorted or only the top or bottom? If both IGBTs are shorted please check the pulses.

 

 

Best Regards,

Akhil Kumar.

 

Sriram_07
Level 2
10 likes given 10 replies posted 5 questions asked
Level 2

Hello Akhil, 

We dont have any waveforms from that moment . There is no short between gate and emitter pins but the pins 8 and 9 are shorted. high and low side igbt of V phase are shorted. Pulses are not overlapping.

In another igbt module there is a short between U phase low side igbt with ground. Gate and emitter of U phase low side igbt are short in this module.

 

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BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

Please share the schematics for review.

 

Best Regards,

Akhil Kumar.

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Sriram_07
Level 2
10 likes given 10 replies posted 5 questions asked
Level 2

the connections to the igbt module alone is fine ? 

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BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

Please share the full schematics.

 

Regards,

Akhil Kumar.

Sriram_07
Level 2
10 likes given 10 replies posted 5 questions asked
Level 2

could you share me your email, i will sent it to you.

Thank you

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BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

Please let me know about the below queries

1) Whether C102 & C103 are DC link capacitors or do you have an external DC link capacitor board?

2) Confirm the values of R7, R8, R9 and R14.

3) Purpose of R14 and R15.

4) Whether the motor is having any issues or is it working fine?

Perform the below tests :

1) Remove the power module, motor and observe the Input and Output PWMs in all gate drivers. Share the waveforms.

2) If you observe that PWMs are fine. Connect only the power module (remove motor) and apply PWMs to Utop and Vbot and observe the voltage across pin 5 and pin 4. If it is working fine, repeat the same test in all phases.

Please let me know if the above points are clear to you before starting the test.

 

Best Regards,

Akhil Kumar.

 

Sriram_07
Level 2
10 likes given 10 replies posted 5 questions asked
Level 2

 

C102 and 103 are high freq filter caps. We have separate dc link capacitors - KEMET C4AQGBW5700P3LK ( 2 in parallel) 70uF 450 V film capacitor. 

R7 R9 and other gate resistors are 2.7 ohm

R14 and R15 are pull down resistors 4.7kohm

R8 and C12 is low pass filter (R8 100 ohm)

Motor is working fine .

We have done the gate driver test but will do the test again. The phase voltage measurement we havent tried it yet . we will do the tests and get back to you with the waveforms. 

Thanks for the quick response.

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Sriram_07
Level 2
10 likes given 10 replies posted 5 questions asked
Level 2

Attaching the gate driver ip and op signals - Green is ip pink is op

6 pics - U high low , V high low and W high low

u_high.pngu_low.pngv_high.pngv_low.pngw_high.pngw_low.png

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BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

Gate Waveforms look fine. Please measure the phase voltages as mentioned in the above test case.

 

Best Regards,

Akhil Kumar.

Sriram_07
Level 2
10 likes given 10 replies posted 5 questions asked
Level 2

Attaching the line - line voltage across phase U and V . Waveform is similar in other lines as well. For 120V dc, we are getting 260V ac . we are probing the voltage in 10x mode. this is the output voltage obtained from the open loop control model . switching freq is 20khz 

SDS00001.png

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BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

1) Can you please confirm to which phases the gate pulses are applied?

2) Is there any load between the phases?

3) Can you please repeat the test with the resistive load and share the waveforms.

 

Best Regards,

Akhil Kumar

Sriram_07
Level 2
10 likes given 10 replies posted 5 questions asked
Level 2

For the above voltage waveform ,  phase U and V gate pulses were applied. It was done with no load with phase terminals open. We will send you the exact gate pulses for the above mentioned line to line voltage output. We have to procure the resistive load bank and it will take some time , is there a work around for the R load testing ?

Best Regards ,

Sriram

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BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

I can see a lot of noise in the waveform (output terminals). This might be due to a setup issue or design issue. Repeat the above test by placing a low capacitance value across the Input terminals.

BandaruAkhil_0-1668424704095.png

 

Best Regards,

Akhil Kumar.

BandaruAkhil
Moderator
Moderator 5 likes given 25 solutions authored 100 sign-ins
Moderator

Hi @Sriram_07 

Please let me know if any other support is required.

 

Best Regards,

Akhil Kumar.

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