Chapter 4 Parameters
4-130
Setting 0: when AVR function is enabled, the drive will calculate the output voltage by actual
DC-bus voltage. The output voltage won’t be changed by DC bus voltage.
Setting 1: when AVR function is disabled, the drive will calculate the output voltage by DC-bus
voltage. The output voltage will be changed by DC bus voltage. It may cause insufficient/over
current.
Setting 2: the drive will disable the AVR during deceleration, such as operated from high speed
to low speed.
Setting 3: the drive will disable the AVR function at stop to accelerate the brake.
When the motor ramps to stop, the deceleration time is longer. When setting this parameter to
2 with auto acceleration/deceleration, the deceleration will be quicker.
Related parameter: Pr.01.16(Auto acceleration / deceleration (refer to Accel/Decel time
setting))
08.19
Software Brake Level
(the Action Level of the Brake resistor)
Unit: V
Settings
115/230V series: 370.0 to 430.0V
Factory Setting: 380.0
460V series: 740.0 to 860.0V
Factory Setting: 760.0
This parameter sets the DC-bus voltage at which the brake chopper is activated. Users can
choose the suitable brake resistor to have the best deceleration. Refer to appendix B for the
information of the brake resistor.
This parameter will be invalid for Frame A models (VFD002E11A/21A/23A,
VFD004E11A/21A/23A/43A, VFD007E21A/23A/43A and VFD022E23A/43A) without brake
chopper for which BUE brake unit must be used.
08.20
Compensation Coefficient for Motor Instability
Settings
0.0~5.0
Factory Setting: 0.0
In V/f control mode, the drift current may cause slight motor vibration in the slip compensation
or torque compensation. It can be ignored if this slight vibration doesn’t affect the application.
The drift current will occur in a specific zone of the motor and it will cause serious motor
vibration. It is recommended to use this parameter(the recommended value is 2.0) to improve
this situation greatly.
The drift current zone of the high-power motors is usually in the low frequency area.
It is recommended to set to more than 2.0.
08.21
OOB Sampling Time
Unit: second
Settings
0.1 to 120.0 sec
Factory Setting: 1.0
08.22
Number of OOB Sampling Times
Settings
0.00 to 32
Factory Setting: 20
08.23
OOB Average Sampling Angle
Settings
Read-only
Factory Setting: #.#
The OOB (Out Of Balance Detection) function can be used with PLC for washing machine.
When multi-function input terminal is enabled (MI=26), it will get
∆θ
value from the settings of
Pr.08.21 and Pr.08.22. PLC or the host controller will decide the motor speed by this t
∆θ
value (Pr.08.23). When
∆θ
value is large, it means unbalanced load. At this moment, it needs
to lower the frequency command by PLC or the host controller. On the other hand, it can be
high-speed operation.
