Load torque (%)
200
100
0
0.3
-100
-200
With torque control, operate within a speed control range of 1:10 on the regenerative side.
Precautions on Setting Constants
If the constants are not set properly, performance may be adversely affected.
If there is a possibility of starting with the motor already rotating, enable the speed search function (b3-
•
01=1).
When lowering a torque limit (L7-
•
the system.
If torque limit acceleration is performed, or if the motor slips at the torque limit causing a CF (control
•
fault), increase N4-08 (proportional gain of speed estimator) in steps of 5 until acceleration and decelera-
tion are performed smoothly. When N4-08 is increased, the torque reference (U1-09) may oscillate. If so,
increase C5-06 (ASR primary delay time) by about 0.050 s.
Precaution on Torque Accuracy
To ensure torque accuracy within the speed control range of 1:10 when the motor is operated by itself at
the minimum frequency and the torque reference (U1-09) is higher than in the medium- and high-speed
ranges, increase the setting of the torque adjustment gain (N4-17) and adjust the torque reference so that it
is about the same as that in the medium and high speed ranges.
Control Modes and Applications
Application examples for the Inverter control modes are provided here.
V/f Control without PG (A1-02 = 0)
V/f control without a PG is suitable for applications where multiple motors are operated with a single Inverter,
such as with multi-motor drives.
1
3
6
), set it to as high a value as possible within the range allowed by
Varispeed G7 Control Modes
Driving torque
Speed (Hz)
60
Regenerative torque
5
10-