PROGRAMMING GUIDE
SINUS PENTA
273/486
The parameters affecting field weakening operation are the following:
• Field Weakening Speed C030
• Field Weakening Time Constant C030a
• No-load Current C021
• Rotor Time Constant C025
The parameters above may be adjusted based on the following:
The motor is not capable of reaching the speed
reference (“Limit St. Speed” displayed and the “Limit”
LED comes ON on the display; “L” displayed on the
7-segment display)
Change one or more of the following parameters:
A) Enable automatic field weakening by setting C030a>0.
B) Decrease speed activating static field weakening C030.
C) Decrease no-load current C021.
During acceleration ramps in field weakening mode,
current limit activates (the “Limit” LED comes ON on
the display and “H” is displayed on the 7-segment
display). The motor is not capable of performing
quick acceleration ramps in field weakening mode.
This means that field weakening is not responsive as required.
Do the following:
A) Enable automatic field weakening by setting C030a>0. If
activated, this means that the time constant set in C030a is too
long, so decrease C030a to increase responsiv
automatic field weakening mode.
B) Decrease the speed value activating static field weakening
C030.
C) Decrease no-load current C021.
Too high current required to deliver motor torque (the
“Limit” LED comes ON on the display and “H” is
displayed on the 7-segment display), o
maximum deliverable torque in field weakening mode
is too low.
This means that the magnetizing current in field weakening
mode is too low. Do the following:
A) Increase C030 in oder to start reducing the magnetization
current as 1/n a
t higher speed, or disable the static field
weakening (C030 = “Disable”). When C030a>0, the automatic
field weakening dynamically reduces the magnetization
current, only if required.
B) Increase no-load current C021 in order to increase the
In field weakening mode, output voltage M027 is
lower than the rated voltage and the DC-link voltage
divided by √2.
This means that the magnetization current in field weaking
mode is too low, so field weakening is excessive for the motor.
This affects the maximum deliverable torque. Do the following:
A) Increase C030,
because the speed value causing the
magnetization current to decrease is too low, or disable static
field weakening by setting C030=Disable.
B) Increase no-load current C021.
In field weakening mode, speed, torque or current
oscillations occur.
This means that the automatic field weakening is too jerky. Do
the following:
A) Increase time constant C030a.
B) Decrease the activation speed for the static field weakening
C030, so
that the automatic field weakening activates less
frequently.
C) Decrease no-load current C021, so that the automatic field
weakening activates less frequently.
Output voltage M027 required at high torque is lower
than the no-load voltage (or at low torque), o
different than the expected torque based on the rated
motor voltage.
This means that the motor flux is weak. This will affect the
maximum deliverable torque. Do the following:
A) Change rotor time constant C025.
B) Disable the static field weakening by setting C030 =
“Disable” (or increase its value)
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