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Old 05-13-2012, 03:35 AM   #717 (permalink)
nlc
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Quote:
Originally Posted by thingstodo View Post
How fast do you need to read the 3 phase currents so that they'll add to 0? Or do you need to average them, since you are sending a bunch of pulses?
In FOC, you always work with instantaneous phase currents, there is no averaging. It's why it's mandatory to have a microcontroller which can do simultaneous sampling on at least two channel.

It's true the controller sends voltage pulses on the motor phases, but the current is smooth, with just a small ondulation, it's why the better is to sample the current in the middle of the voltage pulse, to be in the middle of the ondulation and have the exact current value.
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