Posted on May 17, 2011 at 10:15Using three hall sensors the phase synchronization will be performed each edge of each sensor so 6 times for each electrical period.
The assumption is that the three hall sensors are equally spaced. 120° or 60°. So the syncronization point have been set to these values:
#if (HALL_SENSOR_NUM == 3)
const u16 PhaseVal[]={0,10923,21845,32768,43691,54613};
Consider one electrical cycle equal to 65536 so each edge will occur each 10923 (65536/6)
But if the sensor is not equally spaced the phase sinchronization can be correct for one sensor and fails for the other two.
The phase angle will act by the same ammount for all of the six point so if you have the sensor not equally spaced you can not correct it using a single phase angle.
You can try to change the Phase Val array for instance the elements [1][2][4][5]. You can keep [0] and [3] with the standard values and change the other in paris [1] with [4] and [2] with [5]
Other possibility can be using three different Phase angle.
PS. Are you sure that the sequence of the Hall sensor signal is the one expected (See AN1947)
Best regards
Gigi
