Torque Monitor Function - Omron 3G3MX2 User Manual

5-11 Sensorless Vector Control
If sensorless vector control cannot provide the desired characteristics, adjust the motor
parameters depending on the phenomena, as shown in the table below.
Operation
Power running
Regeneration
During startup
deceleration
5
Low-frequency
operation
Note: To use a motor with a capacity lower than that of the Inverter, set Torque Limit (b041 to b044) by
Example) From the above formula, the torque limit value to achieve α = 200% with a 0.75 kW Inverter and

Torque Monitor Function

This function monitors the estimate output torque of the motor.
This function is enabled only when Sensorless Vector Control is selected for control method
(A044/A244 = 03). Take note that if constant torque characteristics (VC), reduced torque
characteristics (VP 1.7th power) or free V/f setting is selected for Control Method (A044/A244),
this function is disabled and the output signals for display or through the control terminal block
become indeterminable.
To perform monitoring via the Digital Operator, select Display Parameter d012.
To perform monitoring using signals from the control terminal block, refer to "MP Terminal
(Pulse/PWM Output)" on page 5-42 or "AM Terminal (Analog Output)" on page 5-44.
The torque monitor value under this function assumes that the torque corresponding to the
Inverter's rated current is 100%.
Accordingly, the absolute value of torque varies depending on the motor to be combined.
5-151
Phenomenon
status
Speed change ratio is a
negative value.
Speed change ratio is a
positive value.
Insufficient torque at low
frequency (several Hz)
Shock occurs during
startup.
The motor momentarily
rotates in the direction
opposite the reference
rotation direction.
During
Motor hunting
Rotation is not constant.
making sure the value α, calculated with the following formula, does not exceed 200%. Otherwise,
the motor may burn out.
α = Torque limit value × (Inverter capacity) / (Motor capacity)
0.4 kW motor is calculated as follows:
Torque Limit (b041 to b044) = α × (Motor capacity) / (Inverter capacity)
Adjusting method
Increase motor parameter R2
gradually up to the set parameter × 1.2.
Decrease motor parameter R2
gradually up to the set parameter × 0.8.
Increase motor parameter R1
gradually up to the set parameter × 1.2.
Increase motor parameter Io gradually
up to the set parameter × 1.2.
Reduce motor parameter J from the set
parameter.
Reduce the speed response.
Set Reverse Rotation Prevention
Selection (b046) to "01: Enabled."
Reduce motor parameter J from the set
parameter.
Reduce the speed response.
Increase motor parameter J from the
set parameter.
Raise the speed response.
= 200% × (0.4 kW) / (0.75 kW) = 106%.
SYSDRIVE MX2 Series USER'S MANUAL (3G3MX2-A@@@@)
Adjustment
item
H021/H221/
H031/H231
H021/H221/
H031/H231
H020/H220/
H030/H230
H023/H223/
H033/H233
H024/H224/
H034/H234
H005/H205
b046
H024/H224/
H034/H234
H005/H205
H024/H224/
H034/H234
H005/H205