8400 StateLine C | Reference manual
Motor control (MCTRL)
V/f characteristic control - energy-saving (VFCplusEco)
152
L
Firmware
≤
11.00 - DMS 8.0 EN - 10/2011
5.5.5
Remedies for undesired drive behaviour
Drive behaviour
Remedy
Inadequate smooth running at low speeds, especially in
the case of operation with a long motor cable
Automatic motor data identification (
112)
Reduce the influence of the Eco function by increasing
the minimum voltage V/f (
C00977
).
Problems in case of high starting duty (great mass
inertia)
1.Set motor control VFCplus with linear characteristic
(
C00006
= 6).
2.
Adapting the Vmin boost
.
(
134)
3.Again set motor control VFCplusEco (
C00006
= 11).
Drive does not follow the speed setpoint
The current controller intervenes in the set field
frequency to limit the controller output current to the
maximum current (C0022, C0023). Therefore:
• Prolong acceleration/deceleration times:
C00012:
Accel. time - main setpoint
C00013
: Decel. time - main setpoint
• Consider a sufficient magnetising time of the motor.
Depending on the motor power, the magnetising
time amounts to 0.1 ... 0.2 s.
• Increase the maximally permissible current:
C00022
: Imax in motor mode
C00023
: Imax in generator mode
• Make adaptations for the Eco function:
–
Improving the behaviour at high dynamic load
changes
.
(
150)
–
Adapting the slope limitation for lowering the Eco
function
.
(
151)
–
Optimising the cos/phi controller
.
(
151)
Insufficient speed constancy at high load (setpoint and
motor speed are not proportional anymore)
• Increase slip compensation (
C00021
).
Important: Unstable drive due to overcompensation!
• With cyclic load impulses (e. g. centrifugal pump), a
smooth motor characteristic is achieved by smaller
values in
C00021
(possibly negative values).
Note: The slip compensation is only active for operation
without speed feedback.
"Clamp operation active" error message (OC11):
Controller cannot follow dynamic processes, i.e. too
short acceleration/deceleration times in terms of load
ratios.
• Increase the gain of the I
max
controller (
C00073
)
• Reduce the reset time of the I
max
controller (
C00074
)
• Prolong the acceleration time (
C00012
)
• Prolong the deceleration time (
C00013
)
• Make adaptations for the Eco function:
–
Improving the behaviour at high dynamic load
changes
.
(
150)
–
Adapting the slope limitation for lowering the Eco
function
.
(
151)
Motor stalling in the field weakening range
(adaptation especially required for small machines)
• If motor power < inverter power:
Set
C00022
to I
max
= 2 I
rated motor
• Reduce dynamic performance of setpoint generation
• Make adaptations for the Eco function:
–
Improving the behaviour at high dynamic load
changes
.
(
150)
–
Adapting the slope limitation for lowering the Eco
function
.
(
151)
Speed variations in no-load operation for speeds > 1/3
rated speed.
Minimise speed oscillations with oscillation damping
(
C00234
).
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
