Operating Instructions

Descriptions of Parameter Settings
Descriptions of Parameter Settings
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● If the switch point is too low and PM sensorless mode operates at a too low frequency, the motor does not
generate enough back-EMF to let the speed estimator measure the right position and speed of the rotor, and
causes stall and oc when running at the switch point frequency.
● If the switch point is too high, the drive easily runs in the frequency area of the I/F mode for a long time, which
generates more current and cannot save energy. (If the current for Pr.10-31 is too high, the high switch point
makes the drive continue to output with the setting value for Pr.10-31.)
Pr.
Explanation
Settings
Default
10-42
Initial angle detection pulse value
0.0 to 3.0
1.0
● The angle detection is fixed to 3: Use the pulse injection method to start. The parameter influences the value of
the pulse during the angle detection. The larger the pulse, the higher the accuracy of rotor’s position. A larger
pulse might cause oc.
● Increase the parameter when the running direction and the command are opposite during start-up. If oc occurs
at start-up, then decrease the parameter.
● See Adjustment and Application [➙ 255] for detailed motor adjustment procedure.
Pr.
Explanation
Settings
Default
10-49
Zero voltage time during start-up
0.000 to 60.000 sec.
0.000
● This parameter is valid only when the setting of Pr.07-12 (Speed Tracking during Start-up) = 0.
● When the motor is in static state at start-up, this increases the accuracy when estimating angles. In order to put
the motor in static state, set the three-phase of the drive output to the motor to 0 V. The Pr.10-49 setting time is
the length of time for three-phase output at 0V.
● It is possible that even when you apply this parameter, the motor cannot go in to the static state because of
inertia or some external force. If the motor does not go into a complete static state in 0.2 seconds, increase this
setting value appropriately.
● If Pr.10-49 is set too high, the start-up time is longer. If it is too low, then the braking performance is weak.
Pr.
Explanation
Settings
Default
10-51
Injection frequency
0 to 1200 Hz
500
● This parameter is a high frequency injection command in PM SVC control mode, and usually you do not need
to adjust it. But if a motor’s rated frequency (for example, 400 Hz) is too close to the frequency setting for this
parameter (that is, the default of 500 Hz), it affects the accuracy of the angle detection. Refer to the setting for
Pr.01-01 before you adjust this parameter.
● If the setting value for Pr.00-17 is lower than Pr.10-51*10, then increase the frequency of the carrier frequency.
● Pr.10-51 is valid only when Pr.10-53 = 2.
Pr.
Explanation
Settings
Default
10-52
Injection magnitude
115V / 230V models: 100.0V
460V models: 200.0V
575V models: 200.0V
Note: The setting range varies depending on the voltage.
15.0
30.0
37.5
● The parameter is the magnitude command for the high frequency injection signal in PM SVC control mode.
● Increasing the parameter can increase the accuracy of the angle estimation, but the electromagnetic noise
might be louder if the setting value is too high.
● The system uses this parameter when the motor’s parameter is “Auto”. This parameter influences the angle
estimation accuracy.