kappa_am
Full Member level 6
Hi,
I have a question about starting an induction motor that is rotating already, an application like fans. I know that a method used is feeding motor with 10-30% of nominal voltage and change frequency from highest possible frequency toward lower frequencies; whenever highest current is sensed, that frequency is which breakdown torque is generated. By adding a percentage of slip frequency, we can get the rotating speed. Out of curiosity, I ran a simulation. I did not observe current peak around rotating frequency. However, I saw minimum current which indicates synchronous frequency. isn't it better to search for minimum current instead maximum current? Why didn't maximum current show up in the simulation?
Please find the picture of simulation result attached. respectively from top to bottom are current, voltage frequency and rotating frequency (I kept it constant).
I would be grateful if you share your comments.
I have a question about starting an induction motor that is rotating already, an application like fans. I know that a method used is feeding motor with 10-30% of nominal voltage and change frequency from highest possible frequency toward lower frequencies; whenever highest current is sensed, that frequency is which breakdown torque is generated. By adding a percentage of slip frequency, we can get the rotating speed. Out of curiosity, I ran a simulation. I did not observe current peak around rotating frequency. However, I saw minimum current which indicates synchronous frequency. isn't it better to search for minimum current instead maximum current? Why didn't maximum current show up in the simulation?
Please find the picture of simulation result attached. respectively from top to bottom are current, voltage frequency and rotating frequency (I kept it constant).
I would be grateful if you share your comments.