The reciprocating generator of Figure has a movable plunger+ The reciprocating generator of Figure has a movable plunger (position x) which is supported so that it can slide in and out of the magnetic yoke while maintaining a constant air gap of length g on each side adjacent to the yoke. Both the yoke and […]
If the synchronous motor of Problem 5.30 is now operated+ If the synchronous motor of Problem 5.30 is now operated as a synchronous generator connected to an infinite bus of rated voltage, find the minimum per-unit field excitation (where 1.0 per unit is the field current required to achieve rated open-circuit voltage) for which the […]
The rotor of a six-pole synchronous generator is rotating at+ The rotor of a six-pole synchronous generator is rotating at a mechanical speed of 1200 r/min. a. Express this mechanical speed in radians per second. b. What is the frequency of the generated voltage in hertz and in radians per second? c. What mechanical speed […]
The permanent-magnet dc motor of Problem 11.8 is operating at The permanent-magnet dc motor of Problem 11.8 is operating at its rated speed of 3000 r/min and no load. If rated current is suddenly applied to the motor armature in such a direction as to slow the motor down, how long will it take the […]
The manufacturer calculates that the transformer of Problem 2.7 The manufacturer calculates that the transformer of Problem 2.7 has a secondary leakage inductance of 0.225 mH. a. Calculate the magnetizing inductance as referred to the secondary side. b. A voltage of 266 V, 60 Hz is applied to the secondary. Calculate (i) the resultant open-circuit […]
The resistances and leakage reactance’s of a 30-kVA, 60-Hz, The resistances and leakage reactanceâs of a 30-kVA, 60-Hz, 2400-V: 240-V distribution transformer are R1 = 0.68 ? R2 = 0.0068 ?, X11 = 7.8 ? X12 = 0.0780 ? where subscript 1 denotes the 2400-V winding and subscript 2 denotes the 240-V winding. Each quantity […]
The manufacturer’s data sheet for a permanent-magnet dc motor The manufacturer’s data sheet for a permanent-magnet dc motor indicates that it has a torque constant Km = 0.21 V/(rad/sec) and an armature resistance of 1.9O. For a constant applied armature voltage of 85 V dc, calculate a. The no-load speed of the motor in r/min […]
The resistance measured between each pair of slip rings of a he resistance measured between each pair of slip rings of a three-phase, 60-Hz, 250-kW, 16 poles, and wound-rotor induction motor is 49 mO. With the slip tings short-circuited, the full-load slip is 0.041. For the purposes of this problem, it may be assumed that […]
The plunger of a solenoid is connected to a spring. The plunger of a solenoid is connected to a spring. The spring force is given by f = K0 (0.9a â x), where x is the air-gap length. The inductance of the solenoid is of the form L = L0 (1 â x/a), and its […]
The phase windings of the castleated machine of Figure are The phase windings of the castleated machine of Figure are to be excited by turning the phases on and off individually (i.e., only one phase can be on at any given time). a. Describe the sequence of phase excitations required to move the rotor to […]