View Single Post 12-09-2015, 10:49 AM #2458 (permalink) MPaulHolmes PaulH   Join Date: Feb 2008 Location: Maricopa, AZ (sort of. Actually outside of town) Posts: 3,832 Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000 Thanks: 1,368 Thanked 1,202 Times in 765 Posts Oh dear, I made a mistake in my figgerin'. I was thinking I had line to neutral voltage from the DC bus, but it was line to line voltage. I better go re-figger and see what happens. haha Crap, so the 3 phase bridge can make a LINE TO LINE voltage of -DC Bus to +DC Bus. So, the LINE to NEUTRAL voltage can go from -DC Bus / sqrt(3) up to +DC Bus / sqrt(3). So, the 3 phase power is then... Code: ```power = DCBus / sqrt(3) * peakPhaseCurrent * sin(0) * sin(0) + DCBus / sqrt(3) * peakPhaseCurrent * sin(0) * sin(0) + DCBus / sqrt(3) * peakPhaseCurrent * sin(120deg) * sin(120deg) + DCBus / sqrt(3) * peakPhaseCurrent * sin(240deg) * sin(240deg) power = DCBus / sqrt(3) * 1.5 * peakPhaseCurrent power = DCBus * sqrt(3) / 2 * peakPhaseCurrent power = DCBus * sqrt(3/2) * rmsPhaseCurrent So, after the boosting, let's say we have a 700v DC bus, and 50ampRMS phase current. That means: power = 700V * sqrt(3/2) * 50ampRMS = 42866Watt. So, the DC bus current is sqrt(3/2) * 50ampRMS = 61Amp So, the battery bus current is 122amp, so the current through the inductor would be 122amp. The RMS current in the boost switches is 3 times the rms phase current, so is 150amp. At the moment, there are 2 high and 2 low boost switches, so they would have to do 75ampRMS each. Maybe there should be 3 high and 3 low.``` __________________ kits and boards Last edited by MPaulHolmes; 12-09-2015 at 11:34 AM.. 