Rockwell Automation GV3000/SE AC Gen. Purpose & Vector Bookshelf Drive Start-Up and Reference Manual - Manual (Page 143)

Programming Reference 4-57
H.003 Torque Boost Voltage (continued)
The level of increased output frequency is a function of the value entered in H.004 and
the motor current.
Actual motor shaft speed is determined by two factors: inverter output frequency and
the slip of the motor. The speed reference is converted into output frequency. Motor
slip varies with load and is determined by the type of induction motor.
At rated load, slip compensation measures inverter output current and increases the
output frequency by the percentage entered in H.004. Below rated load, slip
compensation will increase inverter output frequency by the percentage in H.004
multiplied by the percent of rated load.
Because of load changes, the long-term speed behavior of the motor is greatly
improved through the use of this parameter.
To calculate the value entered for H.004, use the following equation:
H.004 = 100 x Synchronous RPM - Nameplate RPM x Max Power Module Amps
Synchronous RPM Motor Nominal Current
Figure 4.11 – Torque Boost Voltage

Base Frequency
Voltage
Output
%
Output Frequency
(Hz)


Constant
V/Hz
Ratio
Torque Boost
H.003 = 1%
H.004 Slip Compensation
This parameter is
used to improve
motor speed
regulation by
increasing the output
frequency applied to
the motor (the
percentage of
frequency rise at
Power Module Output
Amps (P.095)). Parameter Range: 0.0% to 10.0% of base frequency (H.001)
Default Setting: 0.0% (no slip compensation)
Parameter Type: Tunable
Refer also to parameters: P.095 Power Module Output Amps
H.001 Motor Nameplate Base Frequency