WEG CFW501 V1.8X, Programming Manual, Page: 82 / 192

V/f Scalar Control
9-6 | CFW501
9
P0137 – Automatic Torque Boost
Adjustable
Range:
0.0 to 30.0 %
Factory
Setting:
0.0 %
Properties: V/f
Access groups
via HMI:
MOTOR
Description:
The automatic torque boost compensates the voltage drop in the stator resistance because of active current.
Look at
Figure 9.1: Block diagram of V/f scale control on page 9-2 , where variable m
IxR
corresponds to the
automatic torque boost action on the modulation index defined by V/f curve.
P0137 actuates similarly to P0136, but the value set is applied proportionally to the output active current in
relation to the maximum current (2xP0295).
The setting criteria of P0137 are the same as those of P0136, that is, set the value as low as possible for the
motor start and operation at low frequencies, because values above those increase the losses, heating and
overload of the motor and inverter.
The block diagram of Figure 9.4: Block diagram of the automatic torque boost on page 9-6 shows the
automatic compensation action IxR responsible for the increment of the voltage in the ramp output according
to the increase of the active current.
Voltage
applied on
motor
Output
active
current
Speed reference
P0139
I x R
P0136
I x R
Automatic
P0137
P0007
Figure 9.4: Block diagram of the automatic torque boost