Saving Energy on Big Slip-Ring Motors Using Recovery Systems

So pick up the phone and talk to a few inverter manufacturers.

read this and apply basic co-generation principles http://iosrjournals.org/iosr-jeee/Papers/ICAET-2014/electrical/volume-1/8.pdf?id=7590

There are several companies making these, but they are getting to be fewer and fewer because people are not using slip ring (wound rotor induction motors) as much any longer.

Slip ring motors are becoming scarce.

Unless it is a particularily large motor (1,000's of hp) it would not be worth while installing a "one off" system.

I studied slip energy recovery back in the 70's, and only once ran across one system that actually used it in all the following years of my career in variable speed drive control. It does allow for some energy recovery, but with the new energy efficient motors and VSD's I doubt you will match the efficiency of a new motor drive system.

What is the application ..

And what is the capacity of motor ..

Presently which type of system is in operation ...

Why did you chosen Slip ring Motor ...is it for High starting torque or is it for Speed control or is it for with standing kick loads ???

Which industry it is installed ...

This CR4 discussion may give you a clue.

Reading the OP again it seems his worry is lost power during start up.

Every Kramer drive I've worked on started normally using resistors of some form. Once the final rotor shorting contactor has closed the Kramer drive is brought on line, followed by the resistance dropping out of circuit.
Therefore there's no saving on start up.

I've got to admit I liked the Kramer system, I've only ever had one fail. That was easily sorted as the drive could revert to normal full speed running and the Kramer system could then be isolated.

You may refer articles below:-

http://electrialstandards.blogspot.in/2014/05/variable-frequency-drive-working.html

http://electrialstandards.blogspot.in/2014/05/power-saving-by-using-variable.html