Originally Posted by z_power
What is your opinion on using 24V starter motor with removed armature as resistive/inductive test load? Isolation is rated a bit on low side but keeping it cool in water bucket should let it last longer.
I'm asking because I can't find big enough inductor for low $ but I have a few starters in ~3 kW range with damaged rotors. Don't know about saturation issues, can you give me a word of advice? Would be great to see waveforms at ~150V 500A without "real" motor test stand.
Hi Mike - 150V 500A will be tough regardless. With a stationary inductor, there is no back EMF so all the voltage rise will have to be purely resistive. Maybe if you wind a big inductor (see some of my earlier posts in this thread for example of my test inductor) with heating wire (high-resistance nickel-chromium alloys usually) and put into water?...
but IMO you don't need full 'motor' voltage to test your controller design. Voltage spikes on transistors will be mostly determined by I^2 and battery voltage. The only problem you won't catch this way is thermal management on the switch. But if you are using half-bridge and diode is integrated in the package, even this error will be small.
just my 2 cents.
Guys - sorry the controller project got put a bit on hold to focus on perfecting our charger (http://www.diyelectriccar.com/forums...-59210p47.html
) and Android EV Dashboard (http://www.emotorwerks.com/emw3/prod...basic-edition/
Now that this is largely done, will spend a bit more time on this.