softstarter 1

[zaza123]

We have a ABB LCI which is used to drive 11.5 MW motor ,which is used for air compressor load.During one start it was observed that the motor was started successfully with softstarter but it could not be synchronised, after some adjustments in guide vane of compressor the motor was successfully synchronised.Can the load torque be a reason or can there be some problem in softstarter

thanks in advance

 

[7anoter4]

The ABB MEGADRIVE LCI is a Static Frequency Converters for soft starting of synchronous machines in power plants. As it mentioned in the ABB explanations [see the link]:
"The control adjusts the actual torque or speed of the motor to the reference value."
In my opinion, that means one has to adjust the reference value so that the ultimate motor speed will facilitate the synchronizing.
If the reference value is set at the maximum value so the only way is to reduce the motor start torque.
The motor required torque depends of course upon the compressor load and in turn upon valve setting. See:

http://library.abb.com/global/scot/.../$File/MEGADRIVE-LCI_for_SoftStarter_Rev0.pdf