SHENZHEN INVT ELECTRIC CO., LTD. CHV160 Operation Manual
48
P4 V/F control parameter
Function
Code
Name
Description
setting
range
Default
Value
P4.00
V/F
curve
setting
0
Linear V/F curve
1
Multipoint V/F curve
2
1.3 exponential decreasing torque V/F curve
3
1.7 exponential decreasing torque V/F curve
4
2.0 exponential decreasing torque V/F curve
0
4
0
0: Linear V/F curve. It is applicable to regular constant torque load.
1: Multipoint V/F curve. V/F curve can be defined through setting (P4.03-P4.08).
2-4: multi- exponential V/F curve. It is applicable to variable torque load, such as blower,
pump and so on. Each exponential curve is shown in following figure:
Figure 6-6 V/F curve diagram
Function
Code
Name
Description
setting
range
Default
Value
P4.01
Torque Boost
0.0%
auto
0.1
30.0
0.0
30.0
1.0
P4.02
Torque Booth
cut-off point
0.0%
50.0%
relative to motor rated
frequency
0.0
50.0
20.0%
Torque Boost is mainly applied to less than cut-off frequency (P4.02). The V/F curve after
boost is shown in following figure. Torque booth can improve the low frequency torque
performance of V/F control.
Based on the load, a torque should be chosen properly. For heavy load, increase the torque
boost, but the torque boost should not be set too big, which will result in the motor operating at
overexcitation and that it could be overheated, and also the inverter output current is big,
reducing efficiency.
When the torque boost is set as 0.0%, the inverter is at automatic torque boost.
Torque boost cut-off frequency: below this frequency, torque boost is valid, and above this
frequency setting, torque boost is invalid.
