In Reply to: Help for Inverter Design using IGBTs posted by Dharmadhikari V.B. on 01/28/00 at 11:22 AM:
: I am in need of a design / schematic of
: a 3 Phase inverter suitable to drive 50 HP
: induction motor.
: If anyone knows the links or can send the information
: please help me.
: Can anyone provide the links to application notes
: of IGBTs ( Inverter design )?
: Dharmadhikari V. B.
: Lecturer in Electronics Engg.
: Walchand College of Engg.
: Sangli. (INDIA) 416415
I did some work on a 35KW IGBT based inverter a number of years ago, when these devices were very new. We used a Plessy chip (now GPS), the MA828 to provide the digital modulation. It was quite good, but some of the control features that I would have liked wern't available. One point that we found was important was the physical layout of the DC link. The solution we adopted (I believe since we talked with the Tosh. apps guys it's now a 'standard technique' - Cheers for the recognition guys!) We used a double sided (min. 3 oz copper) PCB for the link. The nice screws on top of the devices fit well onto the PCB we designed. This PCB housed the link caps and the rectifiers as well. Because the PCB had the -ve connection on one side of the board, and the +ve on the other, inductance was reduced by flux-canceling, rarther like it is in twisted pairs of wire. The PCB made a very good carrier for the all-important snubbing circuits.
Hope this helps