skylogger wrote: I used to play a bit with the older desktop PC's, and I think I remember that you never power up the ATX Switching power supply without it being plugged into the mother board, or a dummy load, or the power supply would blow up. I was wondering if this IMIEV Charger and DC-DC Converter might be simular.
I don't believe so. I operated a lot of older Elcon/TC chargers on the bench with no load and had no problems. Of course, the iMiEV chargers could be different, but my gut feeling is no. Switching the DC-DC (12 V charger) with no load might be a different story, but I'm pretty certain that merely applying power and no CAN signals, no switching will happen, and no damage will be done. Applying a small 12 V battery for charging on the bench is a lot easier and safer than a 360 VDC battery.
Also, if there is no load on the 360vdc output, do you think the charger could be tested for short periods of time without coolant running through it, like testing it on a bench instead of fitting back in the car?
Again, I did this all the time on the Elcon/TC chargers. I'd say the iMiEV chargers would be fine on the bench with no cooling.
I'm a great fan of running these chargers initially at least from a current limited power supply. [ Edit: Into the mains input. The DC-DC might similarly work with much lower voltage at the 360 V input. ] I settled on 52 V (two 26 V 3 A power supplies in series) for the Elcon/TC chargers. This was enough to get the power supply chip working, and if enabled, the PFC stage could boost the 52 V (more like 50 V after the input rectifier) to the ~385 V that the power stage wanted. There were in fact jumpers (really just pairs of pads labelled something like J8) that could be used to first switch the output stage at 50 V, then if that worked, switch at 385 V (some 64x the energy in the bus capacitors with 8 times the voltage). There was even a jumper to cause the output stage to switch even though the microcontroller wasn't yet commanding output, and it wasn't seeing a battery to charge. This would put some 120% of maximum voltage at the output if all was working. By working methodically through the procedure, you'd be able to test the power stages with gradually increasing power levels, minimising the chances of having things blow up on the bench. I would never apply mains power till the charger was back together (apart from the cover with 28 screws), so the 400 V parts were safely tucked away, and the MOSFETs had their heatsink clips on. These Elcon/TC chargers were only air cooled.[ Edit: heatsinks on -> heatsink clips on ][ Edit: 120% of rated -> 120% of maximum ]