Taffy-
I took Paul's advice and looked in on Ian Hooper's design of a 600 A motor controller
Zero Emission Vehicles Australia
It has some interesting design items, like the bus bars. I am still trying to understand Paul's schematic, but I do more mechanical than electrical and it is nto coming easy. Still wondering, Paul, are you using a PCB board for the bus bars with your 500 A controller? Ian replied to a question I had for him about an update and the current status of his controller. Here is what he said:
Hi Graham,
Ah yes it was great to see Paul's success with his motor controller
development - I know from experience how challenging it can be!
My latest prototype from December is still going strong, the only
change since then has been to add a larger heatsink plus cooling fans.
This eliminates the heating problem of course but personally I think
forced convection is a bit of a workaround for what is evidently a
somewhat inefficient design! Synchronous rectification would help a
lot (but is difficult to implement), and there may be ways to shorten
switching times (and hence reduce heat) as well.. I'm also concerned
with the lack of cycle-by-cycle current limiting; another thing to add.
So I guess in short I'm not particularly happy with the design yet,
and I don't think it's "bulletproof" enough for public consumption!
But hopefully it'll get there eventually..
Kind regards,
Ian Hooper
Any thoughts on his concerns about the heating and switching rates? Bulletproofing? Thanks for the component list and source info, and the schematic.