Commissioning
5.3 Preparing for commissioning
Converter with the control units CU240D-2
Operating Instructions, 04/2018, FW V4.9 SP10, A5E34262100B AF
87
5.3.2
Selecting the control mode
Suitable applications and typical control properties
U/f control or FCC (flux current con-
trol) without an encoder
Vector control without an encod-
er
Vector control with encoder
Application
examples
•
Horizontal conveyor technology
(conveyor belts, roller conveyors,
chain conveyors)
•
Pumps, fans, and compressors
with flow characteristic
•
Horizontal conveyor technol-
ogy (conveyor belts, roller
conveyors, chain conveyors)
•
Extruder
•
Centrifuges
•
Pumps and compressors with
displacement machines
•
Vertical conveyor technolo-
gy (conveyor belts, roller
conveyors, chain convey-
ors)
•
Lifters/Lowerers
•
Stacker cranes
Motors that
can be oper-
ated
Induction motors
Induction motors
Encoderless 1FK7 synchronous
motors
Reluctance motors
Induction motors
The rated current of the motor must lie in the range of 13 % … 100 % of the rated current of the inverter.
Properties of
closed-loop
motor control
•
Responds to speed changes with
a typical settling time of
100 ms … 200 ms
•
Responds to load surges with a
typical settling time of 500 ms
•
U/f and FCC are suitable for the
following cases:
–
For power-up times 0
→
rated
speed > 2 s
–
For applications with increas-
ing load torque without load
impulses
•
The closed-loop control is insensi-
tive to inaccurate motor data set-
tings, e.g. the motor temperature
•
The vector control responds to speed changes with a typical
settling time of < 100 ms.
•
The vector control responds to load impulses with a typical
settling time of 200 ms.
•
The vector control is required in the following cases:
–
For power-up times 0
→
rated speed < 2 s
–
For applications with fast and high load impulses
•
Typically achieves a torque
accuracy of ± 5 % for 15
% … 100 % of the rated
speed
•
Extends the torque accura-
cy of ± 5 % to speeds
< 15 % of the rated speed.
Max. output
frequency
550 Hz
240 Hz
Torque con-
trol
Closed-loop torque control not possi-
ble
Torque control for speeds >
15 % of the rated speed
Torque control from speeds = 0.