Category Archives:
Essay Writing Help

Linear induction motors have been proposed for a variety of Linear induction motors have been proposed for a variety of applications including high-speed ground transportation. A linear motor based on the induction-motor principle consists of a car riding on a track. The track is a developed squirrel-cage winding, and the car, which is 4.5 m […]

Small single-phase permanent-magnet ac generators are frequently Small single-phase permanent-magnet ac generators are frequently used to generate the power for lights on bicycles. For this application, these generators are typically designed with a significant amount of leakage inductance in their armature winding. A simple model for these generators is an ac voltage source ea(t) = […]

The constant-speed magnetization curve for a 25-kW, 250-V dc The constant-speed magnetization curve for a 25-kW, 250-V dc machine at a speed of 1200 r/min is shown in Figure. This machine is separately excited and has an armature resistance of 0.14O. This machine is to be operated as a dc generator while driven from a […]

A square voltage wave having a fundamental frequency of 60 A square voltage wave having a fundamental frequency of 60 Hz and equal positive and negative half cycles of amplitude E is applied to a 1000-turn winding surrounding a closed iron core of 1.25 x 10–3 m2 cross section. Neglect both the winding resistance and […]

The 145 MW hydroelectric generator of Problem 5.15 is operating The generator of Problem 5.22 achieves rated open-circuit armature voltage at a field curren A synchronous machine with a synchronous reactance of 1.28 per unit is operating as a generator at a real power loading of 0.6 per unit connected to a system with a […]

The 145 MW hydroelectric generator of Problem 5.15 is operating The generator of Problem 5.22 achieves rated open-circuit armature voltage at a field current of 850 A. It is operating on the system of Problem 5.22 with its voltage regulator set to maintain the terminal voltage at 0.99 per unit (23.8 kV). a. Use MATLAB […]

A three-phase induction motor, operating at rated voltage and A three-phase induction motor, operating at rated voltage and frequency, has a starting torque of 135 percent and a maximum torque of 220 percent, both with respect to its rated-load torque. Neglecting the effects of stator resistance and rotational losses and assuming constant rotor resistance, determine: […]

Stray leakage fields will induce rotor-frequency voltages in a p The nameplate on a 460-V, 50-hp, 60-Hz, four-pole induction motor indicates that its speed at rated load is 1755 r/min. Assume the motor to be operating at rated load. a. What is the slip of the rotor? b. What is the frequency of the rotor […]

Ro = 4.0 cm h = 2cm g = 0.2 cm Calculate: a. the b. Repeat the calculation of part (a) for the case in which the core and plunger are composed of a nonlinea .A three-phase Y-? transformer is rated 225-kV: 24-kV, 400 MVA and has a series reactance of 11.7 ? as referred […]

Ro = 4.0 cm h = 2cm g = 0.2 cm Calculate: a. the b. Repeat the calculation of part (a) for the case in which the core and plunger are composed of a nonlinear material whose permeability is given by where Bm is the magnetic flux density in the material. c. For the nonlinear […]