Ok, i formed 4 isolated 15V supply. Connected all pins except gate pins.
Didn't apply dc bus voltage. I tried to make to conduct the igbts by applying 5V to their gates which is obtained their own supply by resistor divide. But none of the igbts went into the conduction. So what may be the problem? I don't believe that driving an igbt is a very hard thing. But i always failed to make it work properly. The reason that i choose an ipm is to eliminate my inexperience but i couldn't make it work also. Is there a curse on me?