A three-phase star-connected alternator working at 1800 KVA,50 Hz,2100 V, has an armature dc resistance of 0.15 Q. Assume the ac resistance is 1.5 times the dc resistance. A field current of 65 A produces a short circuit current of 37O A and for the same field current the open circuit voltage is 1000 V. Determine a} Synchronous reactance of the machine b) Full load regulation at 0.7 leading c) Power angle a)

A three-phase star-connected alternator working at 1800 KVA,50 Hz,2100 V, has an armature dc resistance of 0.15 Q. Assume the ac resistance is 1.5 times the dc resistance. A field current of 65 A produces a short circuit current of 37O A and for the same field current the open circuit voltage is 1000 V. Determine a} Synchronous reactance of the machine b) Full load regulation at 0.7 leading c) Power angle a)

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

See similar textbooks

Similar questions

The maximum speed of an alternator working at 60 Hz is possible when the number of poles of the machine is ........ a. 4 b. 5 c. 3 d. 2
A 2MVA, 2.3kV three – phase Y – connected alternator operates at rated kVA at a power factor of 80%. The dc armature winding resistance between terminals is 0.08 ohm. The field takes 70 A at 125 V from an exciter equipment. Friction and windage loss is 20kW, iron losses 36kW and stray load losses are 2.0 kW. Calculate the efficiency of the alternator. Assume the effective armature winding resistance is 120% of the DC resistance. a. 94.0 % b. 92.1 % c. 93.2 % d. 89.5 %
A 1200 kVA, 6600 volts, three-phase wye connected alternator, has an effectiveresistance of 2.5 ohms and a reactance of 12 ohms per phase. Determine the inducedemf and the torque developed by the armature when fully loaded at 0.8 leading power factor.
Two 60MVA, alternators operate in parallel. The setting of the governor are such that the rise in speed from full load to no load is 2% in one machine and 3% in the other, the characteristics being straight lines in both cases. If each machine is fully loaded when the total load is 120MW, what will be the load on the first machine (with 2% speed regulation) when the total load is reduced to 80MW?
UDng a ITIe Core in high frequency transformers. c- Discuss, different applications of iron cores of different hysteresis loops. d- Explain the effect of Inrush current on power transformers.
4.) A transformer has a primary coil with 300 windings, and secondary coil has 400 windings. The input AC power supply is 120 volts (Vrms). A) Is this a step-up or step-down transformer? B) What is the rms voltage across the output terminals (Vrms)? C) What is the peak voltage across the output terminals (Vmax)? Primary Secondary imm ac input
Generate a conclusion on this following statements: Determine and analyze the voltage regulation characteristics of the alternator with resistive, capacitive, and inductive loading.
A three-phase induction motor operates at a slip of 3% and has a rotor copper loss of 300W. The rotational loss is 1500W. Determine (a) the airgap power and (b) the power output.
A three-phase star-connected alternator working at 1400 KVA,50 Hz, 2300 V, has an armature dc resistance of 0.15 2. Assume the ac resistance is 1.4 times the dc resistance. A field current of 75 A produces a short circuit current of 360 A and for the same field current the open circuit voltage is 1000 V. Determine a) Synchronous reactance of the machine b) Full load regulation at 0.9 leading c) Power angle a) b)
A 9.9 kV, Y-connected, 3 phase alternator has a synchronous reactance of 8 ohms per phase and negligible resistance. At a certain field current the armature is known to induce 8.2 kV per phase. Calculate the power that can be developed by the alternator at this excitation.
A 30 MVA, 11KV, 50 Hz, star-connected three-phase alternator has an effective armature resistance per phase = 0.020 and synchronous reactance per phase = 2.252. Find the % regulation for a power factor of 0.707 lagging. What is the load angle of the alternator under this condition?
Q1) A single-phase AC voltage controller is connected to an inductive load with a resistance of 10 and load impedance angle of 45°. The input ac voltage is 230 V at 50 Hz. (a) Draw the load voltage waveforms and derive an expression for the rms load voltage. (b) Determine the maximum load voltage, maximum load current, and range of delay angie for which the load voltage does not change.