Can IGBT be replaced with MOSFET?

[joshnz]

I am repairing the motor controller of my neighbors washing machine after it decided to self destruct once it had completed its cycle.

Theses motor controllers control a 3 phase permanent magnet motor
has 6 IGBT transistors two for each phase one upper and one lower
but has a common fault either the upper or lower short and when the controller turns the other half on... boom!

So I am wondering if I can replace this IRGBC30FD2 with a MOSFET.

I pulled out 2 IR840 out of a newer controller (phase3 model) not realizing this controller (Phase 1) used IGBT not MOSFET, So put the Mosfets in replaced fuse powered on, all good but no break or drive. Powered off checked .22Ohm current sense resistor it was open replaced it now the machine has break and drive but seems to be missing a lower or upper due to it is missing a step.

As the drum is rotating around 5 steps are good but one is missing, I am guessing one of the mosfets are not working (or drive circuit damaged) or one
of the IGBT transistors are open.

[Evil Lurker]

Re: Can IGBT be replaced with MOSFET?

Doubful. IIRC Mosfets can't handle the voltage an IGBT can.

[Longbow]

Re: Can IGBT be replaced with MOSFET?

Theses motor controllers control a 3 phase permanent magnet motor has 6 IGBT transistors two for each phase one upper and one lower
but has a common fault either the upper or lower short and when the controller turns the other half on... boom!

It would be interesting to see the schematic of this arrangement. You don't say if you checked the motor for shorts first - first things first. Second, how did you determine when the IGBT's fail? I'm assuming you tried several of them and are now thinking that IGBT's - the OEM parts - are not up to the job??

So I am wondering if I can replace this IRGBC30FD2 with a MOSFET.

The short answer is no, a MOSFET is not a drop in replacement for an IGBT.

From the quick description of the problem, it sounds like you skipped a few steps in troubleshooting. If the motor has first been proven good, the next step is to replace the smoked drive parts and re-evaluate. Keep in mind that the controller itself might have failed, especially if the devices need a dead-band in the switching drive, which may have disappeared.

[joshnz]

Re: Can IGBT be replaced with MOSFET?

The motor has been replaced, the one that was in there has 2 Ohms across all phases meant to be 13 ohms.

The reason for mosfets is the cost of IGBT's at $10 each .

The two of the igbt's on the Phase A are shorted across all pins.

fisher&paykel don't release their schematic's they have a swap policy at $200 each.

The user was with the machine when it self destructed just finished spin once the drum gets below a certain rpm it uses a electronic brake my guess is by turning on the lower transistors.
I'll be replacing them with IRG4BC30FD @ $7 each

[Longbow]

Re: Can IGBT be replaced with MOSFET?

The controller board itself is faulty, not the power output.

[joshnz]

Re: Can IGBT be replaced with MOSFET?

The controller board itself is faulty, not the power output.

What is this in regard of?

I think the transistors were damaged from low impedance of the motor.

[joshnz]

Re: Can IGBT be replaced with MOSFET?

This post is to thoroughly address all your questions.

Second, how did you determine when the IGBT's fail?

This One failed when the user was waiting for it to finish spin.
The blown drive elements are common in these machines from washing to spin as in this case.

I'm assuming you tried several of them and are now thinking that IGBT's - the OEM parts - are not up to the job??

No just put in mosfets from one of the newer controller not realizing this older model uses igbt's instead.
No if anything id say these are over rated.

The short answer is no, a MOSFET is not a drop in replacement for an IGBT.

From the quick description of the problem, it sounds like you skipped a few steps in troubleshooting. If the motor has first been proven good, the next step is to replace the smoked drive parts and re-evaluate. Keep in mind that the controller itself might have failed, especially if the devices need a dead-band in the switching drive, which may have disappeared.

Motor was bad 2 Ohms instead of 13.
Will have to order new parts and see if missing phase fixes itself.
In my newer machine the mosfets have a dead time in them for this purpose/reason.
My machine killed a pair because of water from leaking pump. Others have had it happen from moisture damage to the hall sensor/rotor position sensor.

My description of the missing phase maybe due to a open IGBT yet to test the other 4.
Voltage wise the mosfets should be getting enough gate voltage.
otherwise one of the gate drives has died.