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danieldennie
Level 1
Level 1
First like given First reply posted First question asked

Hi There, I was using TOSHIBA VFS15 Inverter that have FP15R12W1T4 IGBT module inside.

It's running well for over 4 months, then suddenly the Inverter unit blows up, and when i do a deeper check, the Diode (on S and T terminal) are blown, even the pin are seems shorter than usual.

Let's make discussion regarding any cause of the blown Diode? 

Honestly i wasn't so sure to fixing this Inverter using brand new IGBT module before i know what exactly the cause of the explosion.

 

 

Thanks guys!

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1 Solution
Anil_Y
Moderator
Moderator
Moderator
10 likes received 25 solutions authored 10 solutions authored

Dear @danieldennie ,

Good day!!

Please use the following few scenarios to evaluate yourself that the board is a healthy environment to replace:

1) check the healthy condition of pre-charge circuit.( some times relay contact will be closed permanently )

2) Check the healthy condition of input under voltage protection circuit.

3) improper alignment of components on PCB board will lead to high parasitic inductance in the conduction path.

Due to this parasitic inductance high Lp*di/dt drop will appear across the diode, which will reduce the life time of power electronic components.

These could be reasons for failure of diodes in rectifier from myside, may be other possibilities also will be there.

Please give more details, such as schematics, waveforms, and any justifications from your perspective, so that we can help you further.

Before you address the root of the fault, we do not advise replacing the module.

 

Best Regards,

Anil Kumar.

View solution in original post

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5 Replies
Anil_Y
Moderator
Moderator
Moderator
10 likes received 25 solutions authored 10 solutions authored

Dear Danial,

Good day!!

Thanks for posting your question in Infineon community.

I kindly request you to please elaborate the failure issue as much as possible.

Initially please check all applied voltage and current ratings are with in the limits given in the datasheet.

 

Best Regards,

Anil Kumar.

 

Hi AK,

Thanks for your response.

I have checked the supply voltage, they are 390V AC, which is still under the limits of datasheet written. We also used an 15 Amperes MCB for this unit as a security measurement.

 

Best regards,

Daniel

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Anil_Y
Moderator
Moderator
Moderator
10 likes received 25 solutions authored 10 solutions authored

Dear @danieldennie 

Good day!!

Reasons for failure of diodes in rectifier are:

1) Failure of pre-charge circuit will results in high inrush currents through the diodes at turn on (DC link capacitor is completely discharged), which may damage the power diodes.

2) A brief drop in load voltage after the recovery of nominal voltage will results in peak currents which are called surge currents. Due to these currents a brief drop in mains will lead to failure of power electronic components.

3) In this type of modules connection to the rectifier diodes at front end is done with bond wires. Surge currents will destroy bond wires.

 

Best Regards,

Anil Kumar.

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Hi AK,

 

Well, in that condition, it is safe to replace IGBT module at the very same unit and environment?

Or we will need another look for the environment to avoid further damage?

 

Thanks, AK!

0 Likes
Anil_Y
Moderator
Moderator
Moderator
10 likes received 25 solutions authored 10 solutions authored

Dear @danieldennie ,

Good day!!

Please use the following few scenarios to evaluate yourself that the board is a healthy environment to replace:

1) check the healthy condition of pre-charge circuit.( some times relay contact will be closed permanently )

2) Check the healthy condition of input under voltage protection circuit.

3) improper alignment of components on PCB board will lead to high parasitic inductance in the conduction path.

Due to this parasitic inductance high Lp*di/dt drop will appear across the diode, which will reduce the life time of power electronic components.

These could be reasons for failure of diodes in rectifier from myside, may be other possibilities also will be there.

Please give more details, such as schematics, waveforms, and any justifications from your perspective, so that we can help you further.

Before you address the root of the fault, we do not advise replacing the module.

 

Best Regards,

Anil Kumar.

0 Likes