Synchronous Speed to Shaft Speed

[Sirsh]

Hi All

I have a standard induction motor torque vs. synchronous speed diagram and I want to calculate the shaft-speed at any point along the curve (from 0% synchronous speed to 100% synchronous speed). I know that the synchronous speed is 1500 rpm at 95% synchronous speed (which is also at full-load), at full-load the induction motor experiences 5% slip.

Now, I know that the equation n_shaft = n_synch*(100-%_slip) will give me the shaft speed at full-load, but I also know that the slip changes as per the amount of torque/synchronous speed.

At 0% synchronous speed there is 100% slip and at 100% synchronous speed there is 0% slip.

Is there any method to how you can calculate the shaft speeds on the information I've presented? 1500rpm synch speed and 5% slip at full-load.

Thank you for your help

 

[Hesch]

Is there any method to how you can calculate the shaft speeds

Yes, I think you can calculate it, at least by numeric methods ( computer simulation ).

You may find an approximate result, using circle diagrams.

Try to Google:
circle diagram of induction motor