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Originally Posted by e*clipse
With a dyno, we still need a HUGE load dump. Pump water? Heat water?
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That's why I suggested 2 MGRs and 2 controllers. The first is in motor mode, the second in regen or generator mode. Connect to the same battery pack. If you are removing 50 kw and regen of 40, you only need to 'top up' 10 kw to keep the system running.
Or you could run for a while just on battery.
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One thought I had was to just build the car in my case with just the front motor. Build the controller so is could supply about 50% more than the rated power ( 75 kW?? ) Measure everything really well, and go do some slow drag races. F=ma. Step the controller's power limit up each run, and allow a LONG cool-down time.
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And monitor the heck out of everything? Sounds like a workable plan.
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url=http://www.powerstream.com/Wire_Size.htm]American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire breaking strength[/url]
for 0.032, AWG20 wire: 10.15Ohms/1000ft 11A max chassis 1.5A max power 27 kHz
for 0.0285, AWG21 wire: 12.8Ohms/1000ft 9A max chassis 1.2A max power 33 kHz
I'm assuming "power" wiring is continuous, "chassis" wiring is for short-term bursts. I'm assuming for motor use, they're using someplace in between because these wires are bundled and can't dissipate heat like a single strand.
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I'm not sure about the 'power' column. I've never seen anyone use currents that low for the cables involved. For example, #16 lists 22A for chassis and 3.7A for power. That's your house wiring. It'll take 15A all day, every day. #14 is used for outside plugs - 32A chassis, 5.9 for power.