Multi-motor drive of asynchronous motors

Multi-motor drive means the electrical parallel connection of several identical asynchronous motors at 1 inverter, that are rigidly and mechanically coupled and drive a load.

Parallel operation of several identical asynchronous motors is possible provided the strict compliance with the following conditions:

• Only use gearmotors of the same type and with the same winding data.
• The rotor position of the individual motors must not differ in more than the following mechanical angle:
• Z_p × Δφ_{mech_max} < 20°
• Z_p = Number of motor pole pairs
• Δφ_{mech_max} = Maximum torsion angle of the shaft connection in regard of the motor shaft
• This must be ensured by the mechanics, even for maximally different torque loads of the motor shafts.

The maximum number of motors depends on the control mode: