A reluctance motor having the form shown in Fig.1 has an axial length z of 20 cm, a rotor radius r of 10 cm, and an air gap g of 1 mm. The stator and rotor poles have angular widths of 90°.
a. Using any reasonable assumptions, determine the reluctance of the magnetic system as a function of the angle θ. What is the minimum value of this reluctance?
b. If the fringing flux is neglected in part (a), the value obtained for the reluctance is infinite at θ = 0. Suppose the fringing is such to limit the maximum value of the reluctance to four times the minimum value. Show that the reluctance can be represented approximately by the expression (as H-1)
ℛ=5.06×104(2.5+1.5)
c. Suppose a voltage of 110 V (RMS) at 60 Hz is applied to the 15-turn winding. If the winding resistance is negligible, determine the magnetic flux in the machine.
d. At what angular velocity must the rotor rotate to produce an average torque?
e. What is the maximum value of average torque this machine can produce when connected to a 110 V, 60 Hz supply? What is the maximum mechanical power?

Transcribed Image Text:

행 IⅡ N Fig.1 _d 행 IⅡ N Fig.1 _d

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a To determine the reluctance of the magnetic system as a function of the angle we can make some rea... View the full answer