105
SPX advanced – description of parameters
SPX ADVANCED APPLICATION MANUAL
SVCH0203—October 2017 www.eaton.com
5.7.2 Closed loop settings
Code
ID
Parameter
Notes
P1.7.2.1
627
Magnetizing current at start “start magn curr”
Defines the current that is applied to the motor when the start command is given in
closed loop control. At start this parameter is used together with Magnetizing time
at start to decrease the time when the motor is able to produce nominal torque. In
closed loop control output frequency is not forced to zero while magnetization current
is applied to motor.
P1.7.2.2
628
Magnetizing time at start “start magn time”
Defines the time for how long magnetization current is applied to motor at start.
Magnetizing current at start is used to shorten the time when flux is at nominal level.
This will improve the torque performance at start. The time needed depends on the
motor size, value varying between 100 ms to 3 second. The bigger the motor the more
time it needs. Set this time so that the rotor flux is more than 90 % before speed is
released (Start Zero Speed Time ID615) or mechanical brake is released.
P1.7.2.3
1250
Flux reference “FluxReference”
Reference value for rotor flux. Rotor flux can be reduced by changing the magnetization
current. This, however, also affects the motor model making the torque calculations a
little less accurate. When using this parameter the motor model can compensate the
effect of the different magnetization current in torque calculations.
(
)
f (MotorNomFreq)
f (Out)
when f (Out) > f (MotorNomFreq)
[FW]RotorFlux
=
2
Fn
Output frequency
Flux
Flux
2xFn
75 %
50 %
25 %
P1.7.2.4”
1402
Flux off delay “Flux off delay”
The Flux off delay function will keep the motor magnetized after a stop command
thus making the next start faster because flux is already available in the motor. The
function is used e.g. in a system where several repeated starts are made in short
cycles. The flux level can be adjusted by parameter Stop State Flux.
0 = Flux is not maintained in the motor
>0 = Flux off delay in seconds.
-1 = Flux is maintained indefinitely in the motor
P1.7.2.5
1401
Stop state flux “Stop state flux”
The amount of flux in percentage of the motor nominal flux maintained in the motor
after the drive is stopped. The flux is maintained for the time set by parameter ID1402
Flux Off Delay. This parameter can only be used in closed loop motor control.
