Slip Compensation (Pr. 245 To Pr. 247) - Mitsubishi Electric FR-E720-008 Instruction Manual

Adjustment of the output torque (current) of the motor
4.4.4

Slip compensation (Pr. 245 to Pr. 247)

When V/F control or General-purpose magnetic flux vector control is performed, the inverter output current may be
used to assume motor slip to keep the motor speed constant.
Parameter
Number
245 Rated slip
Slip compensation time
246
constant
Constant-power range
247 slip compensation
selection
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 187)
Slip compensation is validated when the motor rated slip calculated by the following formula is set in Pr. 245. Slip
compensation is not made when Pr. 245 = "0" or "9999".
Rated slip =
REMARKS
When performing slip compensation, the output frequency may become greater than the set frequency. Set the Pr. 1 Maximum
frequency value a little higher than the set frequency.
Slip compensation is always valid when Advanced magnetic flux vector control is selected, the Pr. 245 to Pr. 247 settings are
invalid.
Parameters referred to
Pr. 1 Maximum frequency
Pr. 3 Base frequency
90
Name Initial Value
9999
0.5s
9999
Synchronous speed at base frequency - rated speed
Synchronous speed at base frequency
Refer to page 95
Refer to page 97
V/F V/F V/F GP MFVC GP MFVC GP MFVC
Setting Range
0.01 to 50% Rated motor slip.
0, 9999 No slip compensation
Slip compensation response time. When the
value is made smaller, response will be faster.
0.01 to 10s However, as load inertia is greater, a
regenerative overvoltage fault (E.OV ) is more
liable to occur.
Slip compensation is not made in the constant
0 power range (frequency range above the
frequency set in Pr. 3)
Slip compensation is made in the constant power
9999
range.
Description
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