SPEED CONTROL(V/F) OF 3 PHASE IND. MOTOR

T

Thread Starter

TARIQ

I have designed a 4 pole three phase induction motor with very large airgap. We want to use it at very low speed range i.e below 50 rpm. At this moment we are in the simulation phase. For this purpose we are implying constant V/f technique. As intended operation is on very low frequency so we have to increase voltage to compensate satator resistance drop. Could anyone guide me in which ratio or according to which formula i should increase the terminal voltage keeping in mind the very large air gap and very precise torque around 1-2 Nm.
 
Well, unless you have to use V/f technique in control, then (Flux Vector Control) will be a direct solution.
 
i have a book that countians this formula. and it's for this situation

Us= |Rs+jwsls)k+jwsM| Im

where
k =1+ ((ws-wr)^2lrM+jRs(ws-wr)M)/(Rs^2+[(ws-wr)lr]^2)

using yhis equation you can keep the flux constant and therefor control the machine at low speed.
 
U
hi

i want the simulation of v/f control of 3ph induction motor as we are concentrating this project. as for now we started this project and we are collecting some materials. u could have done it already, so please send it by mail the documents related as well as simulation model file.
 
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