I don't know if this has been posted before but I think this is a very good piece of information:
It shows pretty well what to include in the small gate driver PCB and how to physically design and decouple the DC bus. Just get these right and you should be fine...
IGBT half-bridge modules are very easy to use and need a relatively low number of external components. AC controller is easier than many people think. Of course you can make it as complex as you want, but the basic case is simple, as shown in this thread very well.
We use ACNW3130 as gate drivers (similar if not the same as referred in this thread?); they cost something around $6 per piece and you need 6. It can supply 2 amps (with gate resistor about 10 ohms). With the gate capacitance of our 1200V150A IGBT bricks, this means 0.2 Ás RC time - better multiply that by 5 to be sure; so this will limit the rise time by about 1 Ás in our case. If high switching frequencies are desired at high power levels, a stronger driver might be necessary, but we will go with those, too. They are optoisolated and have under-voltage lock-out. Having a voltage range of 30V, I'm thinking about having +18/-10V drive. Yes they specify you can live with single-sided supply, but having a negative drive will
make switching off faster and more reliable.
You also should pay some attention to driving the LED of the optocoupler; it can fire off falsely from inductive coupling of the wiring. ACNW3130 datasheet specifies a certain way to connect the LED when driven from an open-drain output, but IMHO this is not needed with a typical CMOS push-pull output; but this should be kept in mind.