Igbt for AC 32A switch

Question

I have been around this forum, and I am not sure I found my answer. I would like to realize a small and cheap AC switch. Relays being too big, I got interested in IGBT.

The goal is to turn on and off a standard 220Vrms AC with a maximum load of 32A. I figured out that IGBT could be a good alternative because of their high voltage/current performances. As speed is not a constraint here, it seems to be better than Mosfet.

Here is what I image I could do: There is no isolation in the 5V generator as no one is supposed to acces it (wireless control).

I would like to know if my circuit above is correct, and what would be the characteristics required for the IGBT to handle 220Vac 32A. For example, I had a look to this one: http://www.onsemi.com/PowerSolutions/product.do?id=TIG065E8 I feel it is a little too small to handle this job... but I can't see any solid reason in the datasheet showing that it cannot.

Thank you for any help.

Answer 1

Good circuit idea, but I think that will be neither cheap nor small. For each IGBT you'll pay around 1 USD + 1 USD for each 600V diode (D1, D2). So ~ 4USD for the power parts is pretty expensive.

I would have a look for a Triac 16A D2PAK (~40USDcent) and a opto triac (~20USDcent) for driving it from a controller. I'm not sure about the 32Amps because normal household fuses are limited to 16 Amps. But with a TOP3 Triac 40 Amps with proper cooling is also possible.

Any way, the proposed circuit should work. I did a simulation in LTSpice and driving the IGBT should be possible. I've found an IGBT simulation model here.

But I think the gate drive circuit won't be easy to create with-out opto isolation because for Q1 you have to apply 12V against GND (or load) (that's easy) but for Q2 you'll need 12V against Line voltage.

I haven't found a way for driving. In the simple simulation that is working I have used two independend voltage sources to create the drive voltage.