A 2300-V, 800 HP, 0.8-PF leading, 60-Hz, two-pole, Y-connected synchronous motor has a synchronous reactance of 2.5 Q and an armature resistance of 0.3 Q. At 60 Hz, its friction and windage losses are 40 KW, its core losses are 20 KW, and its stray losses are 2.5 KW This machine is operating at rated conditions, and its copper losses is estimated as 12 % of its input power. What is the efficiency of this motor? Select one: O a. %n = 88.65 % O b. %n = 79.7 % O c. %n = 83.16 % O d. None O e. %n = 74.28 % Clear my choice

A 2300-V, 800 HP, 0.8-PF leading, 60-Hz, two-pole, Y-connected synchronous motor has a synchronous reactance of 2.5 Q and an armature resistance of 0.3 Q. At 60 Hz, its friction and windage losses are 40 KW, its core losses are 20 KW, and its stray losses are 2.5 KW This machine is operating at rated conditions, and its copper losses is estimated as 12 % of its input power. What is the efficiency of this motor? Select one: O a. %n = 88.65 % O b. %n = 79.7 % O c. %n = 83.16 % O d. None O e. %n = 74.28 % Clear my choice

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

6. Given the number 0XA0BOCODOE0F0, a. How many bytes for this number b. How many bits for this number c. Store in 8-bit computer with little endian system, and the starting address is 0x123, please show thedata memory map d. Store in 8-bit computer with big endian system, and the starting address is 0x123, please show the data memory map
A hybrid stepper motor has four stator poles and two 5-pole permanent magnet armatures, as shown in Figure Q3. A1 armature 1 armalure 2 A2 Figure Q3 Describe how the motor can be excited by a two-phase source to rotate in the counterclockwise direction.
Q2- A 6 pole lap connected DC generator has 480 turns ,the resistance of each turn is 0.03 Q, the flux per pole is 0.042 Wb and the machine is driven at 1200 rpm. Find E, and terminal voltage at full load armature current of 45 A
(Given plate values of a delta connected 50 Hz synchronous motor are, 380V, 30kW, PF-0,9 (leading) has a synchronous reactance value of 3 ohm . Core (magnetic) losses are 2 kW, electrical losses 4 kW and the rest of the losses for this machine (mechanical friction and ventilation losses) are 1,5 kW. Find the High Side current, Low Side current and Electromotive force and armature current values of this motor under full load (rated load) (30 kW) condition.
4. A 15 HP, 440 volt Compound Self excited DC Motor has a shunt field resistance of 293 ohms and takes 28.5 ampere at rated load when it operate at 1150 RPM. What will be the
A 3 phase , 6 pole , 400 V , 50 Hz , induction motor has R2= 0.1 ohm /ph , X2= 0.8 ohm /ph and the induced emf between slip rings at standstill is 160 V , Assume the friction losses is 300 W. find :- a) the torque output at slip =3% . b) critical slip and the torque maximum .
Q) A separately excited de generator is rated for a load voltage of 150 V for a full load current of 20 A at 1500 rpm. With the load disconnected, the output voltage is 160 V. 1. Determine the voltage regulation, the load resistance, the armature resistance, and the developed torque at full load. 2. The speed of the generator is decreased to 1200 rpm, and the load resistance is unchanged. Determine the load current, the load voltage, and the developed power. Solution:
A 230 V DC Shunt motor runs at 700 r.p.m. and takes armature current of 40 A. Find resistance to be added to the field circult to increase speed to 1200 r.p.m. at an armature current of 60 A. Assume flux proportional to field current. Armature resistance = 0.12 n and field winding resistance is 115h
Q4 A 220 V shunt motor has an armature resistance of 0.5 N and take armature current of 40 A at full-load. By how much must the main flux be reduced to raise the speed by 50 % if the developed torque is constant?
A 240-V shunt motor has an armature and shunt field resistances of 0.20 and 120 Ohms respectively. This motor draws 50 A of current from its source. Its rotational losses amount to 1000 W. If the brush contact drop is 2 V total, find the motor's counter emf in volts
A 3-phase, 48 kW, start-connected permanent magnet (PM) motor has a rated speed of 6600 rpm when supplied from a 110 Hz supply. The d-axis and q-axis inductances are La= 3.5mH and Lg= 4.7mH, respectively. The armature resistance and rotational losses are negligible. The motor operates without field weakening up to 6600 rpm, and a negative direct-axis current is imposed if the motor operates at speeds above 6600 rpm. The no-load terminal line-to-line voltage at 5000 rpm is 420 V (RMS). a. Determine the permanent magnet flux linkage. b. Calculate the rated phase current. c. Calculate the rated line to line voltage of the PM motor. с. d. At a speed of 7300 rpm, the PM motor operates in field weakening mode with a direct axis current of -30A and produces a torque of 30 Nm. Determine the per-phase current at this operating condition.
In a spinning industry, a 225 V, 8 pole shunt motor runs at a speed of 1450 rpm gives an output of 8 HP with an armature current of 32 A. The armature winding is wave-connected and it has 780 conductors. Its armature resistance is 0.1 Q and drop at each brush is 1 V. Find (i) Useful torque, (ii) Total torque, (iii) Useful flux per pole and (iv) Rotational losses occurring in the motor. [ 1HP= 746 W] Useful Torque Total Torque Flux per pole Rotational Loss in the Motor