Delta Tau Geo MACRO, Руководство пользователя и справочное руководство

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Geo MACRO Drive User Manual
88 Setting Up Turbo Motor Operation
usually by exchanging two of the motor phase leads at the drive.
Note:
Because I100 has been set to 0, and I103 may not yet have been set properly, any
change of position will not be reflected in the motor position window.
Setting Up Hall Commutation Sensors
Many motor manufactures now give the consumer the option of placing both Hall effect sensors and
quadrature encoders on the end shaft of brushless motors. This will allow the controller to estimate the
rotor magnetic field orientation and adjusts the command among the motor phases properly without
rotating the motor at power-up. If this is not done properly, the motor or amplifier could be damaged.
Three-phase digital hall-effect position sensors (or their equivalent) are popular for commutation
feedback. They can also be used with Turbo PMAC as low-resolution position/velocity sensors. As
commutation position sensors, typically, they are just used by Turbo PMAC for approximate power-up
phase position; ongoing phase position is derived from the same high-resolution encoder that is used for
servo feedback. (Many controllers and amplifiers use these hall sensors as their only commutation
position feedback, starting and ongoing, but that is a lower-performance technique.)
Many optical encoders have hall tracks. These commutation tracks provide signal outputs equivalent to
those of magnetic hall commutation sensors, but use optical means to create the signals.
Note:
These digital hall-effect position sensors should not be confused with analog hall-
effect current sensors used in many amplifiers to provide current feedback data for
the current loop.
Signal Format
Digital hall sensors provide three digital signals that are a function of the position of the motor, each
nominally with 50% duty cycle, and nominally one-third cycle apart. (This format is often called 120
o
spacing. Turbo PMAC has no automatic hardware or software features to work with 60
o
spacing.) This
format provides six distinct states per cycle of the signal. Typically, one cycle of the signal set
corresponds to one electrical cycle, or pole pair, of the motor. These sensors, then, can provide absolute
(if low resolution) information about where the motor is in its commutation cycle, and eliminate the need
to do a power-on phasing search operation.
Note:
In the case of magnetic hall sensors, the feedback signals often come back to the
controller in the same cable as the motor power leads. In this case, the possibility