Yaskawa A1000 AC Drive - Manual (Page 12)

2 Overvoltage Suppression A1000 Custom Software
12 YASKAWA TM.A1000SW.062 Overvoltage Suppression A1000 Custom Software Supplement
„ Motor Torque Ramp During Start
Overview
This function is intended for machines which require a higher starting torque and control of separate torque limits during
motor start.
Detailed Description
When a run command is first issued, the drive will internally use parameter P3-01 as both the forward and the reverse
motoring torque limit, for the time specified in parameter P3-02. When the P3-02 time expires, the torque limit ramps
back to the L7-01 & L7-02 values, at a rate determined by parameter P3-03. The time set into parameter P3-03 represents
a torque limit change of 100%. P3-02 can be more than, less than, or the same as L7-01 or L7-02. This function is
disabled during auto-tuning.
Example: If P3-01 = 200%, L7-01 = 50%, and P3-03 = 2.0 seconds, the torque limit ramp time would be calculated as
follows:
ΔTorque Limit =P3-01 - L7-01 = 200% - 50% = 150%
Ramp Time =
ΔTorque Limit × P3-03/100% = (150% × 2.0)/100% = 3.0 seconds
Figure 3
Figure 3 Motoring Torque Limit at Start
Limitations
Torque Ramp During Start is only active in the OLV control mode (A1-02 = 2).
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