Active Discharge circuit for large electrical motor

[eerocketman]

Hello,

I am currently working on an active discharge safety circuit for a very large electrical motor to trigger at the event of an emergency stop.

Can anyone advise me as to whether an IGBT or relay is the best option for the main discharge switch. I am dealing with around 100 Amps at a max voltage of up to 500V.

[Circlotron]

What exactly do you want to discharge? A motor itself has nothing to discharge. Is it a large DC link capacitor in a variable speed drive?

[jordanp123]

If your working with a large motor, then you may have access to antiquated or obsolete motor starter contactors, if so I would just use one of them, they are very robust, without looking anything up your looking at a NEMA 2 or so.

[endevor100]

If you're using a VFD or similar drive most of them have build in circuitry to do this. Brake resistor and regenerative resistor are terms I've seen on wiring diagrams. My understanding is that this is usually done with the IGBT both because of speed and cost.

You are taking about a load of 50kW. For your own safety you should consider that if you have to ask this question you might not be able to foresee all of the potential dangers to yourself and your equipment from your design. You have a lot of potential to do hard with this much power, be smart.