Question:
Is it possible to operate two motors parallel at a 9300 servo, and which motor parameters are to be entered?
Answer:
The operation of two asynchronous motors at one servo controller is possible, if the corresponding selection and the following advices are considered:
- Only identical motors can be used
- They must be coupled shrunk to each other.
- Both motors connected parallel are detected by the drive controller as a summated motor.
- Only one feedback system is to be connected to the drive controller.
- The parallel operation of synchronous motors is not possible.
- Only one KTY temperature sensor is to be connected to the drive controller.
- For the second motor a second thermal monitoring is eventually to be installed (PTY, thermal contact).
For setting parameters we advise the following procedure:
- Selection of a motor in C0086 with a total power, which corresponds to the sum power of both motors, so that the corresponding standard settings can be loaded for the regulation parameter (speed controller and current controller).
Then following values are to be entered deviating from the nameplate data of
one motor:
- C0081 - Motor rated power: Double the value
- C0088 - Motor rated current: Double the value
- C0084 - Stator resistor: Divide the value in two
- C0085 - Leakage inductance: Divide the value in two
- C0022 (Imax) - max. current: to be adapted according to the requirements (double).
After the parameter setting we recommend a control, as well as eventually an optimisation of the current controller setting according to the 9300 servo inverter operating instructions (Chapter 5).
Tip:
Idle running:
If two asynchronous motors are operated in parallel and in idle running, even without friction-locked coupling, the motor without friction is expected to run without any problems.
Synchronous motors:
It is
practically not possible to operate two synchronous motors in parallel at one controller as described above. In theory it would be possible to couple two synchronous motors directly with a shaft and to align the rotors of the motors in a way that both rotor angles are an exact match. In this special case the parallel operation of two synchronous motors at one controller could be possible (we have, however, no experience so far).
