ABB ACS850 series, Firmware Manual

Page: 169 / 260

Parameters 169
40.04 Voltage reserve Defines the minimum allowed voltage reserve. When the
voltage reserve has decreased to the set value, the drive
enters the field weakening area.
If the intermediate circuit DC voltage
U
dc
= 550 V and the
voltage reserve is 5%, the RMS value of the maximum output
voltage in steady-state operation is
0.95 × 550 V / sqrt(2) = 369 V
The dynamic performance of the motor control in the field
weakening area can be improved by increasing the voltage
reserve value, but the drive enters the field weakening area
earlier.
-4 … 50% Voltage reserve. 1 = 1%
40.06 Force open loop Defines the speed/position information used by the motor
model.
False Motor model uses the speed feedback selected by parameter
19.02 Speed fb sel .
0
True Motor model uses the internal speed estimate (even when
parameter
19.02 Speed fb sel is set to Enc1 speed / Enc2
speed ).
1
40.07 IR-compensation Defines the relative output voltage boost at zero speed (IR
compensation). The function is useful in applications with a
high break-away torque where direct torque control (DTC
mode) cannot be applied.
See also section IR compensation for a scalar controlled
drive on page 44 .
0.00 … 50.00% Voltage boost at zero speed in percent of nominal motor
voltage. 100 = 1%
42
42 Mech brake ctrl
Mechanical brake control configuration. See also section
Mechanical brake control on page 35 .
42.01 Brake ctrl Activates the brake control function with or without
supervision.
Note: This parameter cannot be changed while the drive is
running.
No Brake control disabled. 0
With ack Brake control enabled with supervision (supervision is
activated by parameter
42.02 Brake acknowl ).
1
No. Name/Value Description FbEq
U / U
N
(%)
f (Hz)
Field weakening point
Relative output voltage. No
IR compensation.
Relative output voltage. IR
compensation set to 15%.
15%
100%