159
SPX advanced – description of parameters
SPX ADVANCED APPLICATION MANUAL
SVCH0203—October 2017 www.eaton.com
7.2 Start position with incremental encoder
without Z-pulse input.
When using incremental encoder without Z-pulse, no actual
identification is made. But start angle is find in every start.
Identification mode can be selected by “P1.8.5.2 Start Angle
Identification Mode” In this case encoder identification
cannot be done because zero position cannot be identified
without Z-pulse. But identification P1.1.9 Identification
selection “2/ID With Run” is needed to make. Identification
at every start will be automatically active if “P1.8.5.1 PMSM
Shaft Position” parameter value is zero.
Best result is get when motor has a mechanical brake
that prevents shaft movements. Acceptable result can be
achieved also when motor has high load and/or inertia that
prevent shaft movements during identification.
Angle identification is done in every start by feeding motor
with a DC pulses that identifies magnet position. DC pulses
are in two different groups. First one identifies zero position
and second one makes polarity check. These DC current
levels are adjusted by “P1.8.5.3 Start Angle Identification
Current” and “P1.8.5.4 Polarity Pulse current”, respectively.
otee:
N
Not all motors are suitable for this
identificationmode. Functionality needs to be tested
beforeproduction use.
Benefit of this mode is that motor can be fully loaded from
the start.
Related parameters:
Related parameters:
Code
ID
Description
Notes
P1.8.5.2
1691
Start Angle Identification Mode
P1.8.5.1
649
PMSM Shaft Position
P1.8.5.3
1759
Start Angle Identification Current
P1.8.5.4
1566
Polarity Pulse current
Code
ID
Description
Notes
P1.1.9
Identification
P1.8.5.1
PMSM Shaft Position
P1.8.5.6
I/f Current
7.3 Identification with incremental encoder with
Z-pulse input.
When using incremental encoder with Z-pulse, identification
is made only once. Remade is needed if encoder and rotor
position changes related to each other.
Motor needs to be able to rotate freely that magnet
positions can be identified. Identification mode
in this case is selected by “P1.1.9 Identification”
selection “3/Enc.ID Run”.
During identification drive feeds DC current to motor
(~90 % of motor nominal), this causes motor to move to
zero position, there may be oscillatory movement on the
shaft. When motor oscillatory movement has stopped
motor is rotated until Z-pulse is received from the encoder.
When identification is successful “P1.8.5.1 PMSM Shaft
Position” is updated, if not successful value is set to zero
and identification warning is displayed for 10 seconds
(W57). If identification is made several times result may be
different, there are as many positions as there are pole pairs
in the motor.
When motor is started and zero position is not
“remembered”: Drive will start to feed DC current to motor
(Defined by “P1.8.5.6 I/f Current”) till Z-pulse is received
from the encoder. During this DC injection motor may not
be able to produce 100 % torque. When running without
load Z-pulse position can be seen in the motor current when
current goes nearly to zero.