Rockwell Automation 21G PowerFlex 750-Series AC Drives Programming Manual User Manual
Page 129
Rockwell Automation Publication 750-PM001J-EN-P - October 2014
129
Drive Port 0 Parameters
Chapter 3
Fil
e
Gr
ou
p
No.
Display Name
Full Name
Description
Values
Re
ad
-Write
Da
ta T
ype
TO
RQUE C
O
N
TROL
In
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ti
a A
dap
ti
on
704
InAdp LdObs Mode
Inertia Adaption Load Observer Mode
Used to enable operation of either Inertia Adaption or Load Observer.
These System Control modes are only available in Vector Control mode when using a
motor speed feedback device. The value of P76 [Total Inertia] must be valid in order for
these features to work correctly. The P70 [Autotune] setting 4 “Inertia Tune” can be used
to measure the System Inertia. Regardless of the Sys Control mode used, the parameter
P707 [Load Estimate] is updated for monitoring purposes. Only active in Flux Vector (FV)
motor control modes (P35).
The possible settings for Sys Control Sel are:
“Disabled” (0) – Both Inertia Adaption and Load Observer functions are disabled. P708
[InertiaTrqAdd] is zero so the motor torque reference is not affected. P707 [Load
Estimate] is still valid, provided that the drive is in Vector Mode, using a motor speed
feedback device, and a valid P76 [Total Inertia] is used.
“InertiaAdapt” (1) – Inertia Adaption function is enabled. The Inertia Adaption function
will provide enhanced stability, higher bandwidths and dynamic stiffness. Inertia
Adaption is especially useful in systems with a gear-box that become, in effect,
disconnected from the load. Inertia Adaption may also be used for motors with very
little inertia that otherwise would lack dynamic stiffness, even at high bandwidths. The
output of the Inertia Adaption function P708 [InertiaTrqAdd], will subtract from the
motor torque reference.
“LoadObserver” (2) – Load Observer function is enabled. The Load Observer function
removes or greatly reduces the effects of load disturbances and provides quicker system
response. The output of the Load Observer function is similar to P707 [Load Estimate],
but has a filter setting determined by P711 [Load Observer BW]. The Load Observer’s
output signal will add to the motor torque reference.
Default:
Options:
0 = “Disabled”
0 = “Disabled”
1 = “InertiaAdapt”
2 = “LoadObserver”
RW 32-bit
Integer
705
Inertia Adapt BW
Inertia Adapt Bandwidth
Sets the bandwidth of a low pass filter located in the output of the Inertia Adaption
function. This parameter should typically be set to match the bandwidth of the drive’s
speed regulator. This matching setting is automatically made when the Inertia Adaption
function is active and the speed regulator bandwidth (P636 [Speed Reg BW]), is set to a
non-zero value. If the speed regulator bandwidth is set to zero, then this filter setting
must be manually adjusted.Only active in Flux Vector (FV) motor control modes (P35).
Units:
Default:
Min/Max:
R/S
10.00
1.00 / 1000.00
RW Real
706
InertiaAdaptGain
Inertia Adaption Gain
Sets a multiplier of system inertia used when the Inertia Adaption function is selected
P704 [InAdp LdObs Mode] = 1 “InertiaAdapt.” This gain has no effect on the parameter
P707 [Load Estimate]. Higher gain values may cause high frequency ringing, while
smaller values may cause fundamental load instability. This gain should typically range
from 0.3 to 1.0 with 0.5 nominal best. The gain setting of 0.5 is automatically made
when the speed regulator bandwidth (P636 [Speed Reg BW]), is set to a non-zero value.
If the speed regulator bandwidth is set to zero, then this gain setting must be manually
adjusted.Only active in Flux Vector (FV) motor control modes (P35).
Default:
Min/Max:
0.500
0.300 / 1.000
RW Real
707
Load Estimate
Load Estimate
Displays an estimated load torque value for the drive. This value is only available in
Vector Control mode when using a motor speed feedback device. The load estimate does
not include any torque required to accelerate or decelerate the motor. In order to be
accurate, the parameter P76 [Total Inertia] must contain a reasonably accurate
value.Only active in Flux Vector (FV) motor control modes (P35).
Units:
Default:
Min/Max:
%
0.00
–/+800.00
RO
Real
755
755
755
755