[thingstodo]

Originally Posted by e*clipse

Regarding motor testing, I've got a few limitations. The first one is I don't have a 50kW dino.

I don't either .. I'm trying to come up with a mechanical setup that will allow two of them to be tied together with belts. Nothing complicated has worked on paper. The simplest would have each MGR equipped with two axles, bearings and mounts, like it's going into a truck. Mount the wheel bearings the correct distance apart, add rims and tires. The tires with almost no pressure so the belt rides within the rim. One will work as motor, the other as generator. So you'd need 2 MGRs and 2 controllers, but the same battery bank should work. This is a tried and true method for putting a load on single motors - couple them together and use a controller for each - never seen it down with a system that includes gearbox and differential.

I know we have belts (they are called powerbands) at my day job that can handle 400 HP but they are not cheap. Sometimes the belts are replaced during a maintenance day, before they are really worn down ... perhaps I can get a gate pass?

Another thought - would running the motor at full power for 60 seconds be worthwhile for a car?

Nope. The 60 seconds is to see whether we are overloading it. If you want to stick to 10 seconds, or 12, or 15 that wold be good as well. It SHOULD be more pronounced and easier to see at 60 seconds.

Would it be possible to test the current-handling capability - not the power - of the stator windings at, say 12V? or perhaps use 120VAC to calculate an RMS AC type power??

Will 12V give you useful numbers? With the phasing tricks that you have already discussed to counter the large back-emf produced by the motor, you'd need to run very slowly to make 12V drive a load. Plus if the motors are not loaded, it will be tough to push much current through.

I guess you could bolt them to your test bench and run your test at STALL. With an AC induction motor, that will give you 6X to 8X full load amps, but that is kinda dependent on the slip. With a PM motor there is no slip so would you just be putting pulses, almost like DC, to one set of coils, like a servo, trying to rotate it?? The switched reluctance .. would maybe work that way too? Set up the magnetic field to make the rotor want to rotate and align the magnetic lines of flux?

I have no experience in this - just thinking out loud.

Once you get into the 120VAC range, you have reached 20% of the rated voltage so I would expect 20% of the current - 10 kw - hard to generate without a controller.

Perhaps if you had a 12V battery charger, one of those booster types that will put out like 200A for a few seconds to start up a car. That is done with a transformer inside, so you may be able to get to the 12VAC before it gets rectified with diodes. If you were to connect that to the MGR, with a contactor/starter ... you could measure one phase with a clamp-on meter during start, and if you figure out how to put a load onto the axles (but it would need to be both axles?) you could watch the current rise .. until you melted the battery charger. But the voltage is low, so 60 Hz may not be slow enough to do a decent current test?

Lots of unknowns on this one.