Tests were carried out on a three-phase 220 V, 50 Hz, 4-poledelta-connected induction motor. The followingresults were obtained from open circuit (no-load) and short circuittests.
            OpenCircuit (no-load) Test
Applied Stator Voltage VLine (V) | Stator Line Current ILine (A) | Total Input Power Pin (W) |
240 | 9.6 | 536 |
220 | 7.2 | 420 |
200 | 5.4 | 352 |
180 | 4.3 | 304 |
160 | 3.5 | 276 |
140 | 3.0 | 248 |
120 | 2.5 | 224 |
            ShortCircuit (locked rotor) Test
Applied Stator Voltage VLine (V) | Stator Line Current ILine (A) | Total Input Power Pin (W) |
72 | 14 | 674 |
           A dc resistance test indicates that the stator resistance per phaseis 1.165 W.
a)       Estimate the machine’s friction and windage loss and determine theparameters of the full equivalent circuit of the machine.
Using an appropriate form of the machine equivalent circuit:
b)Â Â Â Â Â Â Â Â Calculate thelosses in the machine and draw a power flow diagram whichillustrates the flow of power through the machine when it runson-load with a slip of 0.06
c)Â Â Â Â Â Â Â Â Determine the starting torque, and also the torque when runningwith a slip of 0.06.
