108
SPX advanced – description of parameters
SPX ADVANCED APPLICATION MANUAL
SVCH0203—October 2017 www.eaton.com
Code
ID
Parameter
Notes
P1.8.3
1278
Torque Select ID1278 “Torque select”
This parameter defines the speed limiting mode in torque control mode. This parameter
can be used as single motor control mode selection when no change is made between
open loop and closed loop controls.
0= “SpeedControl” - Speed control mode
The drive is forced to operate in speed control mode while the motor control mode
parameter is set to torque control mode thus allowing selection of speed control
and torque control mode with single parameter e.g. from Fieldbus.
1 =”MaxFreqLimit” - Positive and negative frequency limits
Speed is not limited by speed reference, only maximum frequency or Positive and
Negative frequency limit if set lower than maximum frequency parameter.
2 =”RampOutput” – Ramp output for both directions
Speed is limited by reference after ramp generator, thus speed will increase with
set ramp time until actual torque is equal to reference torque. If speed is below
reference when load is removed from the shaft the speed will increase without
ramp. This is the default selection. For master follower system it is recommended
to use selection that allows a little higher reference for torque follower that load
will be balanced equally e.g. window control.
3 =”Min” – Minimum from speed reference and torque reference.
The minimum of the speed controller output and the torque reference is selected as
final torque reference.
4 =”Max” – Maximum from speed reference and torque reference
The maximum of the speed controller output and the torque reference is selected
as final torque reference.
5 =”Window” – Window control
Speed is limited within window from speed reference.
Speed control activation limit is different from the speed limit. Speed needs, therefore,
to go first to “Window Pos” or “Window Neg” limit before the speed controller
activates, when speed controller is active speed will be restricted to limit defined by
“Window Pos Off” and “Windows Neg Off” from the “FinalFreqRef”
5.8.1 U/f Settings
U/f settings are mainly used in open loop control modes
with the exception of the Field weakening point voltage
that is also used in closed loop control mode as a limit for
voltage. U/f settings are used to control the voltage level
that are applied to the motor at different frequencies and
different load situations.
Squared
Linear
Programmable
Torque Boost
FWP Voltage
Mid point voltage
U
N
F
N
FWP
Mid point
Frequency
Zero point voltage
What changes are required to start with load from 0 Hz?
•
First set the motor nominal values (Parameter group 2.1)
Option 1: Automatic functions
Step 1: Make identification with rotating motor
Step 2 (If needed): Activate speed control or U/f
optimization (Torque boost).
Step 3 (If needed): Activate both speed control and
U/f optimization.
Option 2: Manual tuning
Step 1: Run the motor using 2/3 of motor nominal
frequency as the frequency reference. Read the motor
current in the monitoring menu or use 9000xDrive
for monitoring. This current shall be set as the motor
magnetization current.
Change the U/f curve ratio selection to programmable (= 2).
Run the motor with zero frequency reference and increase
the motor zero point voltage until the motor current is
approximately same as the motor magnetising current.
(If the motor is in a low frequency area for only short
periods, it is possible to use up to 65 % of the motor
nominal current).
