Delta Tau GEO BRICK DRIVE Manual Do Utilizador
Geo Brick Drive User Manual
Motor Setup
209
High Speed Spindles
With Geo Brick Drives, spindles conceived to operate at higher speeds (e.g. greater than 15,000 rpm)
require the implementation of commutation delay compensation Ixx56. This is also known as phase
advance. It only applies to motors commutated by PMAC.
Ixx56 permits the PMAC to compensate lags in the electrical circuits of the motor phases, and/or
for calculation delays in the commutation, therefore improving high-velocity performance.
The commutation delay compensation Ixx56 is best set experimentally by running the motor at high
speeds, monitoring the current draw (e.g. using the current calculation PLC) and finding the setting that
minimizes the current draw of the motor without causing it go get out of phase (typically triggering a fatal
following error or over current fault on the drive).
Example:
An AC induction motor with a 2048 cts/rev encoder is desired to have a phase advance of 5 “electrical”
degrees at a speed of 30,000 rpm. The system is setup at a 4.5 KHz servo clock. The following equation
can be used to compute an empirical value for Ixx56:
require the implementation of commutation delay compensation Ixx56. This is also known as phase
advance. It only applies to motors commutated by PMAC.
Ixx56 permits the PMAC to compensate lags in the electrical circuits of the motor phases, and/or
for calculation delays in the commutation, therefore improving high-velocity performance.
The commutation delay compensation Ixx56 is best set experimentally by running the motor at high
speeds, monitoring the current draw (e.g. using the current calculation PLC) and finding the setting that
minimizes the current draw of the motor without causing it go get out of phase (typically triggering a fatal
following error or over current fault on the drive).
Example:
An AC induction motor with a 2048 cts/rev encoder is desired to have a phase advance of 5 “electrical”
degrees at a speed of 30,000 rpm. The system is setup at a 4.5 KHz servo clock. The following equation
can be used to compute an empirical value for Ixx56:
#define ServoCycle
4500
; Servo Clock [HZ]
#define Mtr4DesSpeed 30000 ; Max desired speed [rpm]
#define Mtr4EncSF
#define Mtr4EncSF
2048
; Motor #4 Scale Factor [cts/rev]
#define Mtr4PhaAdv
5
; Motor #4 Phase Advance Angle [electrical deg.]
I456=Mtr4PhaAdv*2048*60*ServoCycle/(360*Mtr4DesSpeed*Mtr4EncSF*96*32)
Note
This parameter is especially useful with motors commutated over a
Macro ring.
Macro ring.