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Old 11-17-2014, 01:14 PM   #1325 (permalink)
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Originally Posted by P-hack View Post
Unlikely. If you use a SVPWM switching scheme you are going to get pretty much max torque/rpm as it maximizes phase to phase voltage (which is what maximizes RPM/torque). It would be "hype" to think that FOC is "critical" for max rpm, especially in a synchronous machine. Do you have a link?

Not only SVPWM, I seen many slip control drives having a resolution of 1Hz or worse. The bottom end is FOC generally uses better hardware and therefore performance of such drives is superior. More yet, there has been a great research on FOC and other vector techniques over the last decade or so and it is generally quite easy to take advantage of the work, for example, sensor-less operation.

But if we compare like by like (same hardware, SVPWM, 3rd harmonic, same waveform resolution, CPU and code refinements) the situation changes, on induction machines, this is.

As to e*clipse description on the Prius motor, the standard FOC libraries have nothing to do with high speed operation, but rather torque. You can test bench the motor and it runs fine, but on the road the torque produced will not be satisfactory since the motor is no longer operating on the optimum point.

FOC, itself, will not be the solution for this problem either, hence my question on #1320 on what algorithm was being used to make sure the commutation happens on the right angle depending on the operational characteristics

Of course this doesn't apply directly to induction. Slip control only works for Asynchronous motors.

(and I re-wrote this paragraph as I assumed we were still talking about induction)

Last edited by cts_casemod; 11-17-2014 at 01:39 PM..
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