Goodrive350-19 series VFD Commissioning
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5.10 Commissioning the master/slave function
5.10.1 Master/slave function description
Master/slave control is classified into power balance and speed synchronization.
1. Master/slave power balance
Master/slave power balance is a control method that distributes the load between two or more motors
to achieve even balance. When a transmission device is driven by two or more motors, and two or
more motor shafts are coupled with each other through gears, chains or conveyor belts, it is
necessary to distribute the load between the motors through the master/slave control method to meet
the control accuracy requirements.
High-speed
brake
Fan
Low-speed
brake
Lifting motor 1
Fan
Lifting motor 2
Low-speed
brake
Figure 5.11 Mechanical structure diagram 1
In general, if multiple VFDs control multiple motors through belt connection, it is considered as flexible
connection (or soft connection). When flexible connection is applied, generally, the slave adopts the
speed control mode, and then the droop function is used to achieve better power balance
performance. Therefore, in the terminal master/slave mode, master/slave mode a is recommended; in
the CAN communication master/slave mode, master/slave mode 0 is recommended.
In general, if multiple VFDs control multiple motors through shaft, gear, or chain connection, it is
considered as rigid connection (or hard connection). When rigid connection is applied, generally, the
slave adopts the torque control mode for better power balance performance. Therefore, in the
terminal master/slave mode, master/slave mode b is recommended; in the CAN communication
master/slave mode, master/slave mode 1 is recommended.
