BlueSeas said:
Can you "clock" multiple bldc controllers so the timing is identical?
That would depend on the controller design more than most things.
The thing you have to make sure to avoid is ever having any upper phase bridge half of one controller turn on at the same time as any lower phase bridge half of another controller, for the same phase, because they're directly connected at middle of the bridge (where the motor phase wire goes), and if you ever turn them on at the same time, you just directly shorted battery positive to battery negative thru your FETs and inter-controller-wiring, which while pretty and often spectactular is rarely useful.
If the event is short enough it may just cause excessive heating in those bridge halves, but if it keeps happening, eventually the heat could build up enough to cause a failure anyway.
Any set of identical sensored controllers that uses the same motor hall signals for all controllers in parallel has a chance of working, if all the gate timing has plenty of deadtime between cycles, so that shoot-thru simply never happens.
If the MCU and it's firmware allows you to connect them together to run off one synchronized clock signal, and it doesn't just sync up at the start of running, but does so at every control cycle, it would work. If timing drifts far enough apart to allow "shoot thru", you could (probably would) end up with gameover.
Any controller with opensource firmware could theoretically be programmed for the ability to do this "perfectly", if you know how to do it (I don't). You'd make one controller master, and the other(s) slave(s), and the master's control/timing signals would be used by the slave(s) MCU(s) to start and time their cycles from.
A single phaserunner will not handle the current requirements (or at least the power capability) of a QS 205 hub motor. But can you stack 2 phaserunners, or 2 of anything on the market to get more current?
Not unless you can keep them from ever having shoot thru.
IIRC it has actually been attempted successfully under some circumstances even with generic sensored controllers, though I don't remember the thread name and cant' find it in a 30second search. There's no guarantee it would continue to work, however, as any timing excursion that resulted in shoot-thru would make them go bang.
If you have a motor (or modify one this way) with two or more sets of phase wires, running to non-electrically-connected phase coils in the motor, then you could use any sets of controllers for this you like. (John in CR's "hubmonster" motors work this way) I don't know whether sensored or sensorless would work better in this situation; probably depends on what sensorless detection schemes are used and how the induction from one set of phase coils into the other affected that.