WEG MVW3000 A0040 V023, User Manual

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8-2 | MVW3000
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Special Functions
Slave(s):
On the slave inverter(s), it is necessary to parameterize an analog input of MVC3 board to receive the torque
reference sent by the master inverter.
P0740 (Analog Input 1 Function) = 1 (Torque reference).
NOTE!
Observe the polarity of the analog ones at the moment of the connection between the inverters.
Limitation of the Torque Current - Operation in Vector Mode
As in the previous mode, the master inverter operates in speed control mode, while the slave inverter operates
in torque current regulation mode. Besides the limit value of the torque current, the slave inverter(s) receives the
speed reference signal; therefore, in a potential situation of sudden load reduction, the speed reference is
saturated, thereby avoiding a possible sudden acceleration of the motor.
The speed reference signal sent to the slave inverter(s) must be set to a value slightly above the master inverter
reference. It is recommended to apply an offset to the analog inputs of the slave(s) greater than 5 % added to the
reference sent by the master inverter; the ideal value may vary according to the application.
NOTE!
As the operation with negative torque reference is impossible, this method cannot be used for
regenerative inverters or with dynamic braking.
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...
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MVW3000
Master
Speed
reference
Speed reference
Torque reference
MVC4
AOX
MVC3
AOX
MVC3
AIX
MVC4
AIX
MVC4
AIX
MVC3
AIX
MVW3000
Slave 1
MVW3000
Slave n
Figure 8.2:
General operation scheme of the function
Therefore, the inverters must be parameterized as follows:
Master:
Parameterize one of the analog outputs of the MVC3 board to send the torque current limit to the slave inverter(s).
The example below shows the parameterization of analog output AO1 of the MVC4 board to send the speed
reference.
P0652 (Analog Output 1 Function - MVC3) = 188 (Inverter torque reference).
P0251 (Analog Output 1 Function - MVC4) = 0 (Speed reference).
Slave:
The slave inverter(s) requires the parameterization of an analog input of the MVC3 board to receive the torque
current limit sent by the master inverter. For the speed reference, use the analog input AI1 of the MVC4 board,
whose standard function is the speed reference signal.