IMC102T, Shunt PFC resistor explosed!

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AG_Serad
Level 4
Level 4
First solution authored 25 replies posted 25 sign-ins

 

Hello,

We are using the IMC102T.

We are facing a big problem.

On Power On the board, the R Shunt PFC explosed. The IGBT IFCM15P60GD of PFC is dead (Short ciruit between pin)

 

This board is designed since many month. But We had problem of PFC stability:

PFC voltage is set to 400V. Sometime, PFC not stabilize and over the critical Threshold set to 430V.

To try to correct this, I reduce the configuration of PFC Indcutance into MCEWizard (4 to 3 mH, because 3mH is the nearest to the real Self value)

Then I reduce the parameter 120 - Duty Feedforward factor from 0.85 to 0.16. I seen the 400V voltage was more stable:

0.85: Output voltage oscillate between 398V to 402V.

0.16: Output voltage oscillate between 399.5V et 400.5V.

 

But since, we seen 2 time the problem where the Rshunt PFC explosed.

The PFCTip input threshold is configured to 16A pic (Shunt is 7W).

The 125- PFC overcurrent protection is set to "Cycle-By-Cycle".
PLease, remember problem occurs when motor not move because we are just on power on the AC power. Current need is very low... Then very far than 16A threshold!

PLease could you help me to find a way to investiguate?

Regard

 

Note: Is possible problem can come from the VAC voltage low? Because do to the problem not resovled here:

https://community.infineon.com/t5/iMOTION-controller-driver-IPM/IMC102T-PCF-AC-under-voltage-auto-ac...

I disabled the UnderVoltage detection. In my case, due to a SoftStart InRush CTP with a relay to have a smooth start, It is possible in my case the relay is not activated, so the CTP has a resistor which make decrease AC.

In one case the problem occurs just after re load the script (which drive the relay).

 

In other word, is PFC can cause damage or sur current in case of low VAC voltage even if protection (PFCTrip) is activated?

 

 

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1 Solution
AG_Serad
Level 4
Level 4
First solution authored 25 replies posted 25 sign-ins

Hello

CUrrently, I made some modification:

- PFC OCP mode changed from LatchOff To Cycle-By-Cycle

- Never start PFC on powerOn, but few second later and ensure our SoftStart relay (to avoir InRush current) is driven. THis avoid a lack of AC voltage due to CTP resistor if relay not started and current is asked...

- Tunning Kp, Ki to have a more stable PFC voltage ripple (398V-402V to 399.5V-400.5V)

- Reduce OCP threshold form 28A to 16A, and remove an Added filter on IPFCTRIP (1ms) (Our shunt is 0.05ohm - 7W , but accept 5 time the power (35W) during 5s...)

Until this time, I haven't other Shunt exploded.

View solution in original post

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4 Replies
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @AG_Serad ,

  Can you please let us know the input voltage and also the input rms current at which this is happening ? The inverter is on no load, but is it switching or not switching ?
Is this issue occuring at the startup or in the steady state ?

 "The IGBT IFCM15P60GD of PFC is dead (Short ciruit between pin)" - Which two pins, collector to emitter ?

I'm assuming that the PFC circuit being used looks like the one below. 

psb_0-1646041198427.png

 Kindly share the MCE wizard file so that we can verify the parameters.  Meanwhile, we're analyzing at our end.

Thanks,

Sai

Best Regards,
Sai
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AG_Serad
Level 4
Level 4
First solution authored 25 replies posted 25 sign-ins

Hello,

The input voltage is 220V AC. I don't kno the input current when problem happened.

Then problem append when I powered ON the 220V AC.

The inverter was not on load, but I think it was in runing state. (At this time, If no error on PFC_SWFault, the PFC_Command = 1 was called by the script)

Then I supposed the PFC running.

Now, I modified the script to never start the PFC on startup, but wait an order from serial link.

 

I will transfert to you the mce file and schematic by private message.

All pin was in short circuit (22, 23, 24), I will check the gate driver.

Note: The AC frequency fault was disabled by MCEWizard option. According datasheet, this error is not maskable but MCEWizard allow to diable it.. I don't know if the MCEWizard disabling has an effect? If yes, Is this disabling can cause this issue?

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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Request you to monitor and then capture at around the OV condition and send us the following waveforms so that we can get to the root cause. 
output voltage
gate pulses of the PFC switch
inductor current
VCE of the PFC switch

Note: The AC frequency fault was disabled by MCEWizard option. According datasheet, this error is not maskable but MCEWizard allow to diable it.. I don't know if the MCEWizard disabling has an effect? If yes, Is this disabling can cause this issue?    No, this is no way related to the issue you're mentioning about. Kindly follow the corresponding thread for  an update on this. 

 

Best Regards,
Sai
0 Likes
AG_Serad
Level 4
Level 4
First solution authored 25 replies posted 25 sign-ins

Hello

CUrrently, I made some modification:

- PFC OCP mode changed from LatchOff To Cycle-By-Cycle

- Never start PFC on powerOn, but few second later and ensure our SoftStart relay (to avoir InRush current) is driven. THis avoid a lack of AC voltage due to CTP resistor if relay not started and current is asked...

- Tunning Kp, Ki to have a more stable PFC voltage ripple (398V-402V to 399.5V-400.5V)

- Reduce OCP threshold form 28A to 16A, and remove an Added filter on IPFCTRIP (1ms) (Our shunt is 0.05ohm - 7W , but accept 5 time the power (35W) during 5s...)

Until this time, I haven't other Shunt exploded.

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