A shunt motor operating from a 230-V line draws a full-load A shunt motor operating from a 230-V line draws a full-load armature current of 46.5 A and runs at a speed of 1300 r/min at both no load and full load. The following data is available on this motor: Armature-circuit resistance (including brushes) = […]
A salient-pole synchronous generator with saturated Xd = 0.78 A salient-pole synchronous generator with saturated synchronous reactances Xd = 0.78 per unit and Xq = 0.63 per unit is connected to a rated-voltage infinite bus through an external impedance X bus = 0.09 per unit. a. Assuming the generator to be supplying only reactive power […]
A dc shunt motor operating at an armature terminal voltage A dc shunt motor operating at an armature terminal voltage of 125 V is observed to be operating at a speed of 1180 r/min. When the motor is operated unloaded at the same armature terminal voltage but with an additional resistance of 5 O in […]
A long, thin solenoid of radius r0 and height h A long, thin solenoid of radius r0 and height h is shown in figure. The magnetic field inside such a solenoid is axially directed, essentially uniform and equal to H = Ni/h. The magnetic field outside the solenoid can be shown to be negligible. Calculate […]
Consider a three-phase synchronous motor for which you are given Consider a three-phase synchronous motor for which you are given the following data: Rated line-to-line voltage (V), Rated volt-amperes (VA), Rated frequency (Hz) and speed (r/min), Synchronous reactance in per unit, Field current at rated open-circuit voltage (AFNL) (A). The motor is to be operated […]
Consider the 8-kV: 78-kV, 50-MVA transformer of Problem 2.15 con Consider the 8-kV: 78-kV, 50-MVA transformer of Problem 2.15 connected as an autotransformer. a. Determine the voltage ratings of the high- and low-voltage windings for this connection and the kVA rating of the autotransformer connection. b. Calculate the efficiency of the transformer in this connection […]
A PWM inverter such as that of Figure is operating from a A PWM inverter such as that of Figure is operating from a dc voltage of 75 V and driving a load with L = 53 mH and R = 1.7O. For a switching frequency of 1500 Hz, calculate the average load current, the […]
Consider a 460-V, 25-kW, four-pole, 60-Hz induction motor which Consider a 460-V, 25-kW, four-pole, 60-Hz induction motor which has the following equivalent-circuit parameters in ohms per phase referred to the stator: R1 = 0.103 R2 = 0.225 X1 = 1.10 X2 = 1.13 Xm = 59.4. The motor is to be operated from a variable […]
Consider a three-phase 6/8 VRM. Consider a three-phase 6/8 VRM. The stator phases are excited sequentially, requiting a total time of 15 msec. Find the angular velocity of the rotor in r/min.
Consider a three-phase 6/8 VRM. The stator phases are excited Consider a three-phase 6/8 VRM. The stator phases are excited sequentially, requiting a total time of 15 msec. Find the angular velocity of the rotor in r/min.