Hey,
I'm building a 3 phase variable frequency drive for small (less than 2kW) motors. I've pretty much finished building a prototype circuit and everything is just dandy, except...
My IGBT's keep exploding. Badly exploding...
To try and isolate the problem I built an independant circuit that consisted of a 3 phase rectifier with my IGBT's across the DC bus (as in the picture attached that I found on wikipedia). I had no motor connected, and I had nothing connected to the gate terminal of the IGBT (so they were not being turned on). The IGBT's were rated for 600V 10A, and I was rectifying 415V AC (so it ended up 580VDC). When I flicked the switch they exploded. I had assumed that 2 of these IGBT's in series gave me a voltage rating of 1200V. Maybe not...
So annoyed and with a burnt hand I decided to try a lower voltage. This time I rectified single phase 240VAC (so it ended up 340VDC). This time I tested between the rails of the DC bus to make sure I didn't have a short, and the multimeter read 0.8Mohms. When I flicked the switch the replaced IGBT's exploded again.
I've tested the entire circuit using a 14VDC power supply as the DC bus and it worked well. Anything useful seems to make the IGBT's explode.
Does someone know what's going on here?
I'm building a 3 phase variable frequency drive for small (less than 2kW) motors. I've pretty much finished building a prototype circuit and everything is just dandy, except...
My IGBT's keep exploding. Badly exploding...
To try and isolate the problem I built an independant circuit that consisted of a 3 phase rectifier with my IGBT's across the DC bus (as in the picture attached that I found on wikipedia). I had no motor connected, and I had nothing connected to the gate terminal of the IGBT (so they were not being turned on). The IGBT's were rated for 600V 10A, and I was rectifying 415V AC (so it ended up 580VDC). When I flicked the switch they exploded. I had assumed that 2 of these IGBT's in series gave me a voltage rating of 1200V. Maybe not...
So annoyed and with a burnt hand I decided to try a lower voltage. This time I rectified single phase 240VAC (so it ended up 340VDC). This time I tested between the rails of the DC bus to make sure I didn't have a short, and the multimeter read 0.8Mohms. When I flicked the switch the replaced IGBT's exploded again.
I've tested the entire circuit using a 14VDC power supply as the DC bus and it worked well. Anything useful seems to make the IGBT's explode.
Does someone know what's going on here?