Yaskawa VS-626 MC5 - Manual (Page 147)

7.1 Open-loop Vector Control
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7.1.5 Starting Torque Compensation Function (for SPEC: F)
Starting torque compensation can be input to speed up the torque command at starting with open--loop
vecter control.
This function is effective for mechinery with large friction loads, cranes, and other applications where
starting torque is required. However, this compensation only applies at startup, in contrast to Flux vector
control.
J Starting Torque Compensation Function (C4--03 to C4--05)
User
Change
during Setting Factory
Valid Access Levels User
Constant
Number
Name
during
Opera-
tion
Setting
Range Unit
Factory
Setting Open Loop
Vector
Flux Vector
C4--03
Starting torque com-
pensation value (for-
ward direction)
0.0 to 200.0
0.1
% 0.0 A
C4--04
Starting torque com-
pensation value (reverse
direction)
--200.0 to
0.0
0.1
%
0.0 A
C4--05
Constant for starting
torque compensation
0 to 200
1
ms
10 A
Speed command input
(terminal 13)
Torque compensa-
tion volume
Time constant:
C4--05
Output fre-
quency
Forward (Reverse) com-
mand input (terminal 12) Closed Open
E1--09
Time constant:
C4--02
C4--05 4
C4--03 (forward)
C4--04 (reverse, negative polarity)
The larger between b2--01
and E1--09
The lower limit of Inverter’s torque value is determined by the above torque com--
pensation value.
Fig
7.4 Time Chart for Starting Torque Frequency
D When this function is used, set the starting torque value to the friction load value for ordinary machin-
ery, and to the load for cranes and other lifting devices.
x Friction load: Set the friction load for both C4--03 and C4--04.
x Lifting devices: Set the load for the motor side only (hoist). Do not use this function for lifting de-
vices with counterweights as a shock will be generated if there is a regenerative load.
D Compensation can be set only for the motoring side, for both the forward and reverse directions. It can-
not be set for the regenerative side.
D Starting torque compensation is disabled when switching between forward and reverse after conduct-
ing a speed search.
D Starting torque compensation is always disabled when the second motor is used.
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