Mitsubishi Electric FR-D720S SC EC, Instruction Manual, Page: 182 / 512

Adjust the output torque (current) of the motor Parameter
6 - 32
6.2.3 Slip compensation (Pr. 245 to Pr. 247)
The inverter output current may be used to assume motor slip to keep the motor speed constant.
The above parameters can be set when Pr. 160 = 0.
Slip compensation is validated when the motor rated slip calculated by the following formula is
set to Pr. 245. Slip compensation is not made when Pr. 245 = 0 or 9999.
Pr.
No.
Name
Initial
Value
Setting Range Description Parameters referred to
Refer to
Section
245
Rated slip 9999
0.01–50% Rated motor slip. 1
3
Maximum
frequency
Base frequency 6.3.1
6.4.1
0/9999 No slip compensation
246
Slip compensation time
constant
0.5s 0.01–10s
Slip compensation response time.
When the value is made smaller,
response will be faster. However,
as load inertia is greater, a regen-
erative overvoltage fault (E.OV
)
is more liable to occur.
247
Constant-output region slip
compensation selection
9999
0
Slip compensation is not made in
the constant power range (fre-
quency range above the frequency
set in Pr. 3)
9999
Slip compensation is made in the
constant power range.
NOTES
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.
Rated slip
Synchronous speed at base frequency Rated speed
–
Synchronous speed at base frequency
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100%
×
=