Which is Preferable in Power Electronics --- IGBT or MOSFET ?

[tAhm1D]

Hi,
Due to inherent shortcomings, use of Power Transistors in Power Electronics is very less now a days and its place has been captured by the Mosfets for certain advantages over Power Transistors. Now a days different types of Igbt like discreet or module are available with certain advantages over Mosfet, like no RDS on etc. but Igbt is having VCE sat and low frequency capability drawback which Mosfets are not having. Basing on these points for and against the Mosfet and Igbt, these are used in different circuits. But in general, which is better option in S.M.P.S./Power Electronics? And why? I hope a healthy discussion will be useful for all Power Electronics lovers/practitioners/enthusiasts.

[tAhm1D]

Hi,
Which is better option in smps in greater than 50khz if both are fit for that sort of high frequency- for 1kw SMPS Inverter? Better option in respect of Operational Efficiency? Which one will be cheaper?

Which will be better for 5kw S.M.P.S. Butt Welding Machine?

[Jehan]

If your primary current is very high, the Power dessipation in Mosfets is I2R, but in IGBT it is the VCE Sat, so if you use IGBT the PD will be Ipeak x Vce Sat. also IGBT cost will be lower compared to Mosfets, i use IGBTs in high power designs. in low power designs Mosfets are ok due to Higher frequency and lower losses.

 

[samir]

for low voltage high current application ,mosfet are cheaper but are having higher power loss.Igbt are normally used in motor control application where voltage are greater than 500v.one more advantage of mosfet is that you can Parrnell it for increasing current rating.but one of the worst thing about mosfet is it's inherent body diode having not so good turn off capability(this will create serious problem in hard switching SMPS).
one more advantage is of using IGBT is it's over protection capablity system.in igbt you can simply measure Vce to ensure over current protection.In mosfet you required something like shunt in series with mosfte to detect over current.

[thecic]

tAhm1D,

to add more input to your enquiry I can tell IGBT's aren't very popular for high frequency use, now it's couple of years ago I actually worked with SMPS and inverters professionally and IGBT's suffer from the typical "tail current" if you ever heard, just enter into Goggle the keyword "IGBT tail current" and you will find a lot of information about it, but shortly described the IGBT's turn off slowly and if you measure with a current probe with your oscilloscope you will see the falling edge is very slow in comparison to rising edge of the current wave form.
And no, IGBT's weren't popular for frequencies over 50 KHz in general, but they are also developing and find applications in higher switching frequencies all the time, but so do MOSFET's and push the IGBT's back.
If you are going to design a welding machine then you should go for IGBT's, you don't need very high switching frequency for such an application.

Cheers

[janakfun]

well now a days Power Mosfets are also awwilable to counter the IGBT drawbacks..
You can find more details on google.. just search with the keyword POWER MOSFET.

[ALLPIC]

For faster operation Mosfet is better and for Higher current and voltage IGBT is better for Welding I used IGBT and Home UPS I used Mosfet and For Moror Driver less than 1 hp I used mosfet and rest of them with IGBT

hope this will help

[tAhm1D]

Hi ALLPIC,
Why do you prefer IGBT in Welding Machines and also in bigger powered motors? I have used Mosfets in Welding machine and find it works perfectly. I have not used IGBT much just some TO247/TO218 type, not module type. Hope to test the module type in Welding and Motor Control application soon.
regards.

[ALLPIC]

Actually My welding machine is Spot Welding machine where I done DC bus of 440V and then I made it onece again AC of frequency of 100Hz. For this application I used module IGBT because total current on DC bus will be more than 500A and voltage is also big

[tAhm1D]

Hi Allpic,
Can you please elaborate more regarding your spot welding machine? Why 100 HZ?
regards.

[ALLPIC]

100Hz:- humm nothing but to reduce size of transformer. Then to reduce time to take spot betten 2 metal parts. And ofcource to get more better control. Previously there are thyristator base spot welding controllers available which work on 50Hz but it has very less control on performance of welding quality. But now because of this technique you can even take spot if there is paper bettn 2 metal plates. My controller wait until it burn out and then take regular spot.

[thecic]

I have used Mosfets in Welding machine and find it works perfectly. I have not used IGBT much just some TO247/TO218 type, not module type.

Hi tAhm1D,

did you mean you used MOSFETs in TO247/TO218 package for welding machine, you must have used several to make a useable welding machine I guess, what was the power rating of your welding machine and what frequency did you use?
Good luck!

Regards

[Orcino Borges]

A good article about it.

               Orcino

[tAhm1D]

Hi thecic,
Yes, I used those in parallel. Power required is approximately 10kw and max amp is 300A.

[ALLPIC]

I am aslo looking for >150V and >50A mosfet is there any mosfet available

regards

[kamalakary]

For high voltage and high current IGBT is best for low voltage and low curent MOSFET is best.

[tAhm1D]

I am aslo looking for >150V and >50A mosfet is there any mosfet available

regards

Hi,
There are quite a few of them. I used a few from ST Microelectronics:
STW55NM60ND: 600V, 51A, TO247 package, 60mOhm RDSon
STY60NM60: 600V, 60A, MAX247 package, 60mOhm RDSon
There are some other much more powerful ones in ISOTOP package from STMicroelectronics. You can find the datasheets in the ST Microelectronics website: www.st.com

[Jehan]

For very high power IGBT is the only solution, for low voltage and low power Mosfet