Author Topic: Replacing blown IGBTs on DRSSTC  (Read 947 times)

Offline profdc9

  • High Voltage Engineer
  • ****
  • Posts: 213
  • Karma: +10/-0
    • View Profile
Replacing blown IGBTs on DRSSTC
« on: May 12, 2018, 03:39:01 AM »
I have a full-bridge of IGBTs with 2 IGBTs paralleled in each part of the bridge.

While running the coil, it seems like only two of the eight transistors is damaged.  The other six seem like they're ok, which I established by the crude method of testing to see if the emitter-collector connection is shorted.

Is it safe to reuse the six transistors, or should I toss the six good transistors and get eight new ones?  I think the two transistors that were blown are the two on each side of the half bridge that the bus power shorted through.

Also, can I use a heat gun to remove the supposedly still good transistors from the bottom side of the board?  They are soldered in the TO-247 sockets, or will this damage the transistors too much?

Thanks,

Dan

Offline oneKone

  • High Voltage Engineer
  • ****
  • Posts: 249
  • Karma: +5/-0
    • View Profile
Re: Replacing blown IGBTs on DRSSTC
« Reply #1 on: May 12, 2018, 04:17:36 PM »
I've never had a fullbridge with parallel igbt/mosfets, but multiple times i have just replaced the damaged switching device in the bridge and have left the existing ones in there. For me it's less of a gamble because i use chinese devices. 

Offline Hydron

  • Administrator
  • High Voltage Engineer
  • *****
  • Posts: 226
  • Karma: +6/-0
    • View Profile
Re: Replacing blown IGBTs on DRSSTC
« Reply #2 on: May 12, 2018, 04:50:00 PM »
I'd try and avoid using a heat-gun to remove parts unless you have no choice - even if it doesn't cook the silicon it could still de-laminate the PCB.

As for keeping the rest of the 6 transistors, I am a little confused as to which two you think are blown, but if you still have one of the 2 parallel half-bridges intact on that side of the primary circuit, once you remove the failed devices you could run the coil at low power to check that everything is still OK. A low-voltage (bench PSU) test without a primary circuit and using a signal-generator to supply fake feedback is also a good way to check what's running and whether the IGBTs seem to still work.

Offline Max

  • High Voltage Enthusiast
  • *
  • Posts: 22
  • Karma: +2/-0
    • View Profile
Re: Replacing blown IGBTs on DRSSTC
« Reply #3 on: May 12, 2018, 09:53:52 PM »
Good evening,


In my DRSSTC I also use a paralleled fullbridge, made of 4 SKM200GB128D halfbridge modules. It failed once - severely (ripping the enclosure of one brick in parts). That IGBT Module failed entirely; all of its IGBT and diode dies were black. As the coil has been used successfully after replacing only that module, I'm pretty sure the other three modules aren't damaged.

However ... No crash is like another, so this is absolutely no assurance for you that your other IGBTs are still fine. Even worse: the test you made only works in one direction. If there is a measurable resistance between C and E - and also between the gate and any other pin, then you're sure, that it's damaged. Although an IGBT might pass the test, this unfortunately doesn't mean that it's fine. When I stupidly blew up my driver board, some of the MOSFETs (IRF530 and IRF9530) passed the test (not all) and still didn't work correctly anymore.

As far as I know, there is no better way to measure IGBTs or MOSFETs. So the only thing you can do, is replacing the obviously damaged ones and slowly test your coil as suggested.


Kind regards,
Max

Offline alan sailer

  • High Voltage Enthusiast
  • *
  • Posts: 30
  • Karma: +1/-0
    • View Profile
Re: Replacing blown IGBTs on DRSSTC
« Reply #4 on: May 14, 2018, 03:50:45 PM »
I have not had your direct experience but have replaced one IGBJT is a paralleled pair and been good to go.

Also as far as removing the blown devices the best way is some stuff called ChipQuick (or a generic replacement). It is great, a low temperature (indium based) alloy that you melt into the existing solder. It forms a new alloy that melt at ~100C making it easy to unsolder multiple leads.

It is a good idea to use solder wick to remove the remaining alloy after you are done or else you will have a low temperature melting solder joint.

Cheers.

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 990
  • Karma: +15/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: Replacing blown IGBTs on DRSSTC
« Reply #5 on: May 17, 2018, 10:51:50 AM »
The rest of the MOSFETs / IGBTs might still be working, but have taken some damage, so its hard to say.

Be sure to also check all gate resistors, ZVS, diodes etc. that is on the secondary side of the GDT, often some of those components will die in a inverter explosion and without checking them you can end of changing good IGBTs out again because you think they failed once again.
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline profdc9

  • High Voltage Engineer
  • ****
  • Posts: 213
  • Karma: +10/-0
    • View Profile
Re: Replacing blown IGBTs on DRSSTC
« Reply #6 on: May 17, 2018, 04:08:53 PM »
Here's what I ended up doing.  It's ugly, but it seems to work.

The pads on the blown IGBTs were actually vaporized.  So instead of replacing those, I tried to remove the other IGBTs and place them into a new board.

Unfortunately, desoldering IGBTs ended up being very difficult.  Instead, I cut off the leads of the IGBTs at board level and soldered short 18 gauge wires on the IGBTs as new leads.  This seemed to work ok, and is somewhat more beefy than the original thin leads.  The older thin leads on the IGBTs bent very easily.

Because I have 10 copies of the board I had made, I just soldered the IGBTs into a new board and moved all of the other components, and added 2 more new IGBTs to replace the two that had blown.  Seems to work ok so far, as you can see from the videos.

Dan

Offline Teravolt

  • High Voltage Experimenter
  • **
  • Posts: 92
  • Karma: +1/-0
    • View Profile
Re: Replacing blown IGBTs on DRSSTC
« Reply #7 on: May 17, 2018, 06:31:55 PM »
hi profdc9, what I do is use a 3 position 200 mil spacing terminal block with screws on the board and just bend the legs of the device. it makes it way easier to replace it

High Voltage Forum

Re: Replacing blown IGBTs on DRSSTC
« Reply #7 on: May 17, 2018, 06:31:55 PM »

 


* Recent Topics and Posts

post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
hightemp1
Today at 05:51:09 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
Today at 04:07:17 AM
post Strange GDT signals (need to help)
[Dual Resonant Solid State Tesla coils]
VNTC
Today at 02:19:24 AM
post Re: Easy access to optimal resonance frequency but the benefit is quite small
[Dual Resonant Solid State Tesla coils]
VNTC
Today at 02:00:48 AM
post Re: Strange gdt waveforms
[Dual Resonant Solid State Tesla coils]
VNTC
Today at 01:33:56 AM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
May 22, 2019, 08:31:55 PM
post Re: Easy access to optimal resonance frequency but the benefit is quite small
[Dual Resonant Solid State Tesla coils]
dexter
May 22, 2019, 08:31:51 PM
post Easy access to optimal resonance frequency but the benefit is quite small
[Dual Resonant Solid State Tesla coils]
VNTC
May 21, 2019, 11:35:57 PM
post Re: Offgrid 48V solar to 24V battery setup
[Electronic circuits]
Mads Barnkob
May 21, 2019, 09:59:54 PM
post Re: General Oscilloscope Probing Techniques for (DR)SSTC h-bridge
[Beginners]
Mads Barnkob
May 21, 2019, 09:51:27 PM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
T3sl4co1l
May 21, 2019, 09:49:03 PM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
82026
May 21, 2019, 09:02:10 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 21, 2019, 08:59:57 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
May 21, 2019, 08:28:43 PM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
May 21, 2019, 08:22:28 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 21, 2019, 06:21:37 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 21, 2019, 06:12:55 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
profdc9
May 21, 2019, 04:06:38 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 21, 2019, 03:56:56 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 21, 2019, 03:46:56 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
profdc9
May 21, 2019, 02:32:59 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 21, 2019, 06:12:18 AM
post Re: Offgrid 48V solar to 24V battery setup
[Electronic circuits]
profdc9
May 20, 2019, 11:30:34 PM
post DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 20, 2019, 06:38:54 PM
post Re: General Oscilloscope Probing Techniques for (DR)SSTC h-bridge
[Beginners]
Teravolt
May 20, 2019, 06:33:49 PM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
82026
May 20, 2019, 02:27:59 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
hightemp1
May 20, 2019, 02:57:46 AM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
T3sl4co1l
May 20, 2019, 01:06:27 AM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
82026
May 19, 2019, 09:14:59 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 19, 2019, 06:40:41 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
flyrod
May 19, 2019, 04:04:12 PM
post Re: Offgrid 48V solar to 24V battery setup
[Electronic circuits]
Mads Barnkob
May 19, 2019, 11:24:46 AM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
flyrod
May 19, 2019, 03:22:54 AM
post Re: Are bleeder resistors necessary if I can easily discharge my capacitor?
[Spark gap Tesla coils]
profdc9
May 19, 2019, 03:18:52 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 18, 2019, 10:48:59 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Golddustpeak
May 18, 2019, 04:19:11 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 17, 2019, 10:57:17 PM
post Are bleeder resistors necessary if I can easily discharge my capacitor?
[Spark gap Tesla coils]
jpb133
May 17, 2019, 09:41:56 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Uspring
May 17, 2019, 12:41:17 PM
post ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
82026
May 16, 2019, 04:15:58 PM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Fumeaux
May 16, 2019, 02:19:39 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Golddustpeak
May 16, 2019, 01:50:44 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Uspring
May 16, 2019, 12:17:01 PM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Fumeaux
May 16, 2019, 08:45:15 AM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
May 15, 2019, 11:49:59 PM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Hydron
May 15, 2019, 10:51:33 PM
post Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
May 15, 2019, 09:35:41 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Golddustpeak
May 15, 2019, 05:07:20 PM
post Re: Mounting LCD CFL's around DRSSTC?
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
May 15, 2019, 12:46:33 PM
post Re: General Oscilloscope Probing Techniques for (DR)SSTC h-bridge
[Beginners]
Mads Barnkob
May 15, 2019, 10:08:11 AM

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30