The magnetic circuit of figure has two windings and two The magnetic circuit of figure has two windings and two air gaps. The core can be assumed to be of infinite permeability. The core dimensions are indicated in the figure. a. Assuming coil 1 to be carrying a current Il and the current in coil […]
Read More »The manufacturer’s data sheet for a 26-kV, 750-MVA 60-Hz three-p The manufacturer’s data sheet for a 26-kV, 750-MVA 60-Hz three-phase synchronous generator indicates that it has a synchronous reactance Xs = 2.04 and a leakage reactance Xal = 0.18, both in per unit on the generator base. Calculate (a) The synchronous inductance in mH, (b) […]
Read More »The linear-motor armature of Problem 4.25 has a total active The linear-motor armature of Problem 4.25 has a total active length of 7 wavelengths, with a total of 280 turns per phase with a winding factor kw = 0.91. For an air-gap length of 0.93 cm, calculate the rms magnitude of the balanced three-phase currents […]
Read More »The inductor of Problem 1.13 is to be operated fro The inductor of Problem 1.13 is to be operated from a 60-Hz voltage source. (a) Assuming negligible coil resistance, calculate the rms inductor voltage corresponding to a peak core flux density of 1.5 T. (b) Under this operating condition, calculate the rms current and the […]
Read More »The magnetic circuit of figure and Problem 1.6 has the The magnetic circuit of figure and Problem 1.6 has the following dimensions: Ac = 8.2cm2 lc = 23cm lp = 2.8 cm g = 0.8 mm X0 = 2.5 cm N = 430 turns a. Assuming a constant permeability of Âľ = 2800Âľ0, calculate the […]
Read More »Consider the dc-motor drive system of Problem 10.13. To limit Consider the dc-motor drive system of Problem 10.13. To limit the starting current of the dc motor to twice its rated value, a controller will be used to adjust the initial firing-delay angle of the SCR Bridge. Calculate the required firing-delay angle Îąd. Is this […]
Read More »The inductor of figure has the following dimensions The inductor of figure has the following dimensions: Ac = 1.0 cm2 lc = 15 cm g = 0.8 mm N = 480 turns Neglecting leakage and fringing and assuming Âľr = 1000, calculate the inductance. Is this the question you were looking for? If so, place […]
Read More »The inductor of figure has a core of uniform circular cross The inductor of figure has a core of uniform circular cross-section of area Ac, mean length lc and relative permeability Âľr and an N-turn winding. Write an expression for the inductance L. Is this the question you were looking for? If so, place your […]
Read More »Consider a separately-excited dc motor. Describe the speed varia Consider a separately-excited dc motor. Describe the speed variation of the motor operating unloaded under the following conditions: a. The armature terminal voltage is varied while the field current is held constant. b. The field current is varied while the armature terminal voltage is held constant. […]
Read More »The induction motor of Problem 9.9 is supplied from an unbalance The induction motor of Problem 9.9 is supplied from an unbalanced two phase source by a four-wire feeder having an impedance Z = 0.32 + j1.5O/phase. The source voltages can be expressed as Va = 235 < 0?,=”” va=””> Is this the question you […]
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