Data Sheet

Brushless Motor Connections and Operation
106 Advanced Digital Motor Controller User Manual V1.8, August 28, 2017
0
0
0
22.5
45
45
45
67.5
90
90
90
112.5
135
135
135
157.5
180
180180
202.5
225
225
225
247.5
27
0
270
270
292.5
315
315
315
337.5
Electrical Degrees
Mechanical Degrees
Figure 8-10. Mechanical vs electrical degrees
The reference search will settle on a given electrical angle location. This electrical angle
value exists in 2 mechanical location on this motor. After performing a first search, rotate
the motor shaft and repeat the search. On a perfectly constructed motor, the search will
settle at the same electrical angle on any of the other poles. In practice, it is expected
that the values will be off by one or two degrees from one pole to another. If the value is
consistent from one measurement to another, and difference is larger a few degrees, this
means the poles are not placed with precision in the motor and the motor will not run effi-
ciently. If the difference is very large (20 degrees or more), it is likely that the angle sensor
is not working correctly or that the number of poles of the motor and/or sensor are not
configured correctly.
Important Notice
If the motor is loaded or if there is a lot of friction, the rotor may not be able to
reach the zero angle during the zero-position search. The motor should not be oper-
ated unless it has.
When the zero degree search is done for capturing the offset of absolute sensors (e.g.
sin/cos, resolver or SPI), the angle that is measured by the reference search can be
viewed with the console command
~BADJ ch
The reported values is 0 for 0 degrees and 512 for 360 degrees.
Perform the !BND several times in a row and verify that the same value is captured every time.
Save the offset value permanently to memory with the command
%CLSAV 321654987
This step is only necessary for absolute sensor and must be performed only once.