Hi every one.
I have see the explain text in FOC document on section BLCD alignment procedure and i undrestood that calculation of get current of phase a, b and c was incorrect.
In this article was written current of phase A: voltage / Resistor of a.
But in actual current of phase A: voltage / (Equivalent Resistor)
Equivalent Resistor: (Resistor of A) | (Resistor of B + Resistor of C)
this procedure must be compliance for currents of B and currents of C.
So we’re not measuring across the whole motor, but rather each phase individually.
When measuring the currents, we measure differentially across a shunt resistor, so we get the current flowing through the specific phase.
During the alignment we’re interested in identifying the phase connected to Ua vs the two phases connected to GND. We also want to identify the “direction” of measurement to see if we need to invert the gain. We can do this by supplying a voltage, checking the current of each phase, and finding the phase with double the current of the other two.
Is this what you are referring to? I can’t fully understand your comment…
