Emerson Powerdrive F300 User Manual page 128

Safety Product Mechanical
information information installation
1: Non-salient
If the ratio Lq/Ld < 1.1 on no load then the injection mode cannot be
used and this mode should be used instead. This mode does not provide
the same level of control as injection mode and has the following
restrictions:
• Speed control is possible, but not torque control.
• Spinning start is not possible and the motor must start from
standstill.
• Below Rated Speed (00.045) / 10 it will not be possible to produce
more than approximately 60 % to 70 % of rated torque.
• There may be some movement of the motor shaft in either direction
as the motor starts.
• It is not possible to measure the motor inertia using auto-tuning with
Auto-tune (00.040) = 4.
• Normally the ramp rate should not be slower than 5 s/1000 rpm
when operating in the region below Rated Speed (00.045) / 10.
• This mode is not intended to control the motor for prolonged periods
below Rated Speed (00.045) / 10, but is intended to allow the motor
to be started from standstill to run outside the low speed region.
• This mode is not intended to allow motor reversals. If the direction
does need to be reversed, the motor should be stopped and any
oscillations must die away, before the motor is restarted in the other
direction.
Low Speed Sensorless Mode Current (00.055) defines a current applied
in the motor d axis to aid starting. The default value is suitable for most
motors with a load of up to 60% rated torque. However, in some
applications this level may need to be adjusted.
00.055 {05.071} Low Speed Sensorless Mode Current Limit
RW Num
OL
RFC-A
RFC-S 0.0 to 1000.0 %
Injection mode
For low speed sensorless operation with signal injection (RFC Low
Speed Mode (05.064) = 0) it is necessary to have a ratio of Lq/Ld = 1.1.
Even if a motor has a larger ratio on no load, this ratio normally reduces
as the q axis current is increased from zero. Low Speed Sensorless
Mode Current Limit (05.071) should be set at a level that is lower than
the point where the inductance ratio falls to 1.1. The value of this
parameter is used to define the drive current limits when signal injection
is active and prevent loss of control of the motor.
Non-salient mode
For low speed sensorless operation for non-salient motors (RFC Low
Speed Mode (05.064) = 1) defines a current applied in the d axis to aid
starting. For most motors and applications requiring up to 60 % torque
on starting, the default value is suitable. However the level of current
may need to be increased to make the motor start.
00.056 {05.072} No-load Lq
RW Num
OL
RFC-A
RFC-S 0.0000 to 500.000 mH
Motor q axis inductance with no current in the motor.
128
Electrical Getting Basic
installation started parameters the motor
RA US
20.0 %
RA US
0.000 mH
Running NV Media Card
Optimization
Operation
00.057 {05.075}
RW Num
OL
RFC-A
RFC-S
Maximum test current level used for Iq during auto-tuning when
measuring the motor inductance and phase offset as a percentage of
Rated Current (00.046). This value is also used by the sensorless
control algorithm to define the motor inductance and a reference frame
phase offset at different levels of Iq. The values of Lq At The Defined Iq
Test Current (00.059), and Phase Offset At Iq Test Current (00.058),
should be the values which correspond to the test current level. For most
motors, Phase Offset At Iq Test Current (00.058) will be zero and have
little effect on the performance, however Lq is likely to vary significantly
with Iq and should be set up correctly for good performance. If Lq At The
Defined Iq Test Current (00.059), or Iq Test Current For Inductance
Measurement (00.057) are zero, then the estimate of Lq will not be
affected by the level of Iq, and if Phase Offset At Iq Test Current (00.058)
or Iq Test Current For Inductance Measurement (00.057) are zero the
phase offset will not be affected by the level of Iq.
00.058 {05.077}
RW Num
OL
RFC-A
RFC-S
This parameter defines the offset of the point of minimum inductance as
an electrical angle from the point with no current in the motor, to the point
with a level of Iq equivalent to Iq Test Current For Inductance
Measurement (00.057). When the value is left at its default value of zero,
no compensation for phase offset with changes in Iq are made. Phase
Offset At Iq Test Current (00.058) is used for low speed RFC sensorless
control using injection mode. A positive value advances the point of
minimum inductance with positive Iq. See RFC Low Speed Mode
(00.054). For most motors a value of zero is acceptable.
00.059 {05.078}
RW Num
OL
RFC-A
RFC-S 0.000 to 500.000 mH
Motor q axis inductance with no current in the d axis and the current
defined by Iq Test Current For Inductance Measurement (00.057) in the
q axis of the motor. If this parameter is left at its default value of zero,
then no compensation is made to the value of Lq with changes in Iq.
Onboard Advanced Technical
PLC parameters data
Iq Test Current For Inductance Measurement
0 to 200 %
Phase Offset At Iq Test Current
RA
±90.0 °
Lq At The Defined Iq Test Current
RA
Powerdrive F300 User Guide
UL listing
Diagnostics
information
US
100 %
US
0.0 °
US
0.000 mH
Issue Number: 2