IGBTs versus Mosfets

[ShayanZulfiqar]

Hello, I am designing a pure sine wave h-bridge inverter. Can anyone guide me which one to use out of IGBT and Mosfet and why?

 

[KlausST]

Hi,

select them according:
* current rating
* voltage rating
* switching frequency
* switching loss
* conduction loss
* cost
* availability
.....and so on..

Klaus

 

[bala0x07]

Hi ShayanZulfiqar,

So the answer for your question depends upon your application.

I will mention some of the characteristics of MOSFET and IGBT which will guide you through the selection


* Mosfets have high switching speeds (faster) than IGBT. So if your switching frequency is high, mosfets are the best choice

* MOSFET have better efficiency due to its low series on resistance Rdson. There are also MOSFETs available which can drive more than 100A.

* IGBT have very poor efficiency at lower currents.

* IGBTs are used for High voltage (above 300V) and high current applications. IGBT efficiency improves with greater current handling capacity.

* IGBT finds its application mostly in switching heavy electrical load with lower switching speeds



Hope it helped you

All the best for your task!!!!!

 

[nikhilmahasvar]

IGBT's would be better choice from96V if you are looking for reliable designs. But if the design is cost sensitive you can go up to 120VDC also with MOSFET.
I have designed up to 6KW 72Vdc H bridge with MOSFET and 7.5 KW to 150KW with IGBT (96-650V DC).

 

[KlausST]

Hi,

I´d say this is too general.

Nowadays there are Mosfets rated for 1500V and more.
There are Mosfets with voltage rating >600V and R_DS_ON of less than 30mOhms.

Let´s compare just the voltage_drop vs current of IGBT and MOSFET.
I hope I´ve chosen comparable devices:
MOSFET: STY80NM60N, 600V, 74A, 0.030 Ohms, 10.33€ (@ 100 pieces, Farnell)
IGBT: IHW40N65R5, 650V, 40A, 1.35V, TO247, 2.78€ (@ 100 pieces, Farnell)

Here a chart from the IGBT, where I added the (blue) line for the MOSFET.

You see:
Below about 50A the MOSFET has less voltage drop and thus less power dissipation and better efficiency (regarding conduction loss)
Above 50A the IGBT shows it´s benefit.

For switched applications the current will rise / fall with the switching frequency. Therefore it is very likely that the current sometimes is bleow and sometimes above 50A.

If you calculate with mostly light load, then the MOSFET will have less conduction loss.
But if you expect short time overload, then the IGBT is way more rugged.

And don´t forget the cost.

Klaus