64
Chapter6 P3
V/F
control parameter
P3-05
Multi-point VF
frequency point 2
P3-03
~
P3-07
Default
:
0.00Hz
P3-06
Multi-point VF voltage
point 2
0.0%
~
100.0%
Default
:
0.0%
P3-07
Multi-point VF
frequency point 3
P3-05
~
motor rated frequency
(
P1-04
)
Default
:
0.00Hz
P3-08
Multi-point VF voltage
point 3
0.0%
~
100.0%
Default
:
0.0%
P3-03
~
P3-08 Six parameters define multi-segment V/F curves
。
The multi-point V/F curve should be set according to the load characteristics of the motor.
It should be noted that the relationship between the three voltage points and the frequency
point must satisfy: V1 < V2 < V3, F1 < F2 < F3. Figure 6-4 shows the setting of the multi-
point VF curve.
If the voltage is set too high at low frequencies, the motor may overheat or even burn out.
The inverter may over-current or over-current protection.
。
F3
Fb
F2
F1
V1
V2
V3
Vb
voltage%
Frequency %
V1-V3: Multi-speed V/F section 1-3 voltage percentage
F1-F3: Multi-speed V/F section 1-3 frequency percentage
Vb
:
Motor rated voltage
Fb
:
Motor rated running frequency
6-4 Multi-point V/F curve setting diagram
P3-09
VFSlip
compensation
gain
0.0%
~
200.0%
Default
:
0.0%
The VF slip compensation can compensate the motor speed deviation generated by
the asynchronous motor when the load increases, so that the motor speed can be basically
stabilized when the load changes. The VF slip compensation gain is set to 100.0%, which
means that the motor's rated slip is the motor's rated slip when the rated load is applied,
and the motor's rated slip is obtained. The inverter is calculated by the rated frequency and
rated speed of the P1 motor.
When adjusting the VF slip compensation gain, the motor speed is basically the same