I'm hoping to get an assignment that would entail some testing of both single phase and three phase motor controllers.

How might one model a motor to test a controller? I would need a physical model, parts I can assemble that simulate a real motor being the load.

TIA

 

Might be simplest to model a motor by using ...... an actual motor?

 

One might think so but these units can run from 100 V at 5 A drives up to 600 or 1200 volts at 75 amps. Some single phase H bridges, some three phase. And the thing about a motor is it drives a mechanical brake load, so using actual motors would need not only several motors to cover the ranges but some sort of mechanical load to give the motor something to work on.

Driving a braked motor at near 100 kilowatts is going to get hot, and it's going to get noisy too.

The goal is to have one test stand to cover many controllers. Sure resistive dummy loads still get hot but at least the only noise they make is the fans cooling them.

 

Place I used to work we serviced & installed VFDs and DC drives. We had a "dummy light" test fixture that tell us just the basic "dead or alive" info. It was just a piece of plywood with several arrays of 240V incandescent lights in series & parallel that could be configured to put a load on a drive. But it was almost useless for actual troubleshooting. They can behave a lot differently with an inductive load (and a full load).

For actual testing (above & beyond "dead/alive") we used actual motors. Had a couple of test motor fixtures; motor/generator combos. Occasionally we had to do real tests on real motors of several hundred HP. For this we had to rent a portable load bank for our genny had something to feed.

Sorry to say, if you want to do it right, you need real motors and real loads. It sucks, I know. Sorry.

 

I would think you can either build a load bank meeting your test specifications or have one built. Single phase, poly phase, whatever you want. There are at least a dozen companies who will custom build a load bank you the specifications you call out, Vishay comes to mind as one such company. When I needed some unusual load banks for test and calibration of some unusual power supplies and motor drives I spoke with a Vishay applications engineer and in about 5 weeks we had a working demo to modify. Want data acquisition? That can happen also. You either roll your own or you find someone who does this sort of work and get with their applications engineer(s).

Ron