LCI rating/Motor rating Mismatch

[GTstartup]

Let's say I have a 1 MW LCI Drive but for some reason I want to drive a small synchronous motor, let's say 50HP.

The LCI drive is designed for an input of 1kV but only 480V is available. For the sake of this scenario assume that I can change undervoltage parameters, maximum current parameters etc. Also assume that on the field side I can reduce the current to the correct value for a 50 HP motor.

What are the pitfalls? One I can think of is that the feedback from the stator may not have enough magnitude to allow for correct commutation.

Any other issues? Or can it just not be done?

 

[GTstartup]

P.S. efficiency is not an issue, it's only for a test

 

[jraef]

If I remember correctly, an LCI drive uses the load impedance to switch the power devices in the inverter section, hence the term Load Commutated Inverter. If the impedance of the load is not matched to the drive, it may not work at all. I'm not sure how the matching is done however, so maybe it can be modified in the field. The best people to answer that would be the LCI drive manufacturer.


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[GTstartup]

LCI uses the zero crossing of the voltage of the driven equipment to do the switching. Normally with a drive of this size, feedback from the motor is measured by PTs. With the underrated motor I was thinking of re ratioing the PTs or maybe just a direct connection.

Any other reason why this might not work?