Omron 3G3RX User Manual

4-117
4-2 Function Mode
4
Functions
0-Hz Sensorless Vector Control
•This function enables high-torque operation in the 0-Hz range (0- to 3-Hz frequency reference).
This control method is particularly suitable for applications such as an elevating system, which
requires sufficient torque in a low-frequency range at startup (e.g. crane, hoist).
•To use this function, set V/f characteristics selection A044/A244 to "04".
•To use this function, make sure that the motor parameter settings are suitable for your motor.
(Refer to "Motor Parameter Selection" (page 4-115).)
•The parameters for 0-Hz SLV control are as follows:
•In 0-Hz limit H060/H260, you can set a current value used for constant current control in the 0-
Hz range (generally, 3.0 Hz or lower). This parameter is expressed as a ratio of the output current
to the Inverter's rated current.
•In 0-Hz SLV startup boost amount H061/H261, you can set a current boost amount at startup in
the 0-Hz range. A current value expressed as a ratio to the Inverter's rated current is added to
the current value set in H060/H260 at startup only.
•Note the following before use:
•Select an Inverter with one rank higher in capacity than the motor's.
•Sufficient characteristics may not be obtained if you select a motor size two or more ranks lower
than the maximum applicable motor size.
•In the 0-Hz sensorless control mode, the digital command board (3GAX-DI01) cannot be used.
•If 0-Hz sensorless vector control cannot provide the desired characteristics, adjust the motor
parameters depending on the phenomena, as shown in the table below.
Parameter No. Function name Data Default setting Unit
H060/H260 Limit at 0 Hz
0.0 to 100.0:
Current limit in low frequency range
100.0 %
H061/H261
Boost amount at SLV
startup, 0 Hz
0 to 50: Current boost amount at startup 50 %
Operation
status
Phenomenon Adjusting method Adjustment item
Power
running
Speed change ratio is a
negative value.
Increase motor parameter R2 gradually (up to set
parameter × 1.2).
H021/H221/H031
Speed change ratio is a
positive value.
Reduce motor parameter R2 gradually (down to set
parameter × 0.8).
H021/H221/H031
Regeneration
Insufficient torque at low
frequency (several Hz)
Increase motor parameter R1 gradually (up to set
parameter × 1.2).
H020/H220/H030
Increase motor parameter Io gradually (up to set
parameter × 1.2).
H023/H223/H033
During
startup
Shock occurs during
startup.
Reduce motor parameter J from the set parameter. H024/H224/H034
During
deceleration
Motor hunting
Reduce the speed response. H005/H205
Reduce motor parameter J from the set parameter. H024/H224/H034
Immediately
after
deceleration
Overcurrent or
overvoltage protection is
activated.
Reduce motor parameter Io gradually (down to set
parameter × 0.8).
H023/H223/H033
Set AVR selection A081 to "00" (always ON) or "01"
(always OFF).
A081
Low-
frequency
operation
Rotation is not constant. Increase motor parameter J from the set parameter. H024/H224/H034
Related functions
A001, A044/A244, F001, b040, b041 to b044, H002/H202, H003/H203,
H004/H204, H005/H205, H020/H220, H021/H221, H022/H222, H023/
H223, H024/H224, H050/H250, H051/H251, H052/H252, H060/H260,
H061/H261

Omron 3G3RX Specifications

General

Brand	Omron
Model	3G3RX
Category	DC Drives
Language	English