Of a free excited DC motor, Excitation winding internal resistance R = 50 N, Supply voltage Vr = 100 V Armature winding internal resistance Ra = 0.5 N, Supply voltage Va = 250 V The magnetization (or idle running) characteristic of the machine at n = 1200 rpm is given in the table. Friction and iron losses are neglected. wwww Ir (A) E. (V) 0.5 1 1.5 2 7 70 140 200 238 According to this; a) If = 2 A at excitation current , When working with N = 1200 d/d; b) !; = 2 A at excitation current , When working with N = 1000 d/d; %3D www

Of a free excited DC motor, Excitation winding internal resistance R = 50 N, Supply voltage Vr = 100 V Armature winding internal resistance Ra = 0.5 N, Supply voltage Va = 250 V The magnetization (or idle running) characteristic of the machine at n = 1200 rpm is given in the table. Friction and iron losses are neglected. wwww Ir (A) E. (V) 0.5 1 1.5 2 7 70 140 200 238 According to this; a) If = 2 A at excitation current , When working with N = 1200 d/d; b) !; = 2 A at excitation current , When working with N = 1000 d/d; %3D www

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...

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Consider a separately-excited DC motor with an armature resistance RA= 0.25 N and terminal voltage VT= 120 V. The motor rated speed is 1800 RPM. The field winding supply VF= 36 V and the field resistance is adjustable. The motor has compensating windings and interpoles. IF (A) EA (V) 0.3 85 These values were taken at speed n=1800RPM 0.0 0.1 0.2 0.4 0.5 0.6 0.7 0.8 30 60 102 115 124 130 134 If the motor is driving a load at rated armature current Ia = 46 A, with Radj + Rf=1202. Find the speed of rotation of the motor in RPM. Select one: O a. None O b. Speed n = 1410 RPM O c. Speed n = 1800 RPM O d. Speed n = 2298 RPM
3-phase, 50 Hz, 4-pole, 220 V, 10A ASM has an ASM 0.85 back power coefficient. stator copper losses are 500 W and rotor copper losses are 200 W. Friction and wind losses 100 W, core losses 300 W and stray load losses 50W. According to this; a. Air gap strength b. Mechanical strength produced c. Output power in horsepower D. Yield e. Slipping f. Working Speed g. Torque Produced h. Output Torque i. By specifying the asynchronous Motor power flow diagram from input to outputby drawing?
Of a free excited DC motor, Excitation winding internal resistance Rf = 50 Ω, Supply voltage Vf = 100 V Armature winding internal resistance Ra = 0.5 Ω, Supply voltage Va = 250 V The magnetization (or idle running) characteristic of the machine at n = 1200 rpm is given in the table. Friction and iron losses are neglected. According to this, a) Working with n = 1200 rpm at If = 2 A excitation current, b) Working at n = 1000 rpm at If = 2 A excitation current, Calculate the efficiency with the moment generated.
A180-V, 100 A armature full-load line current, 1500 RPM, cumulatively-compounded DC motor is considered in this problem. Its characteristics are given below: RA + Rs = 0.252 RF = 140 2 Radj = 260 2 NF = 4000 turns NSE = 6 turns This motor has compensating windings and interpoles. The magnetization curve for this motor at 1500RPM is shown in a tabular form below: 0.1 0.2 0.4 0.5 0.6 | 0.8 1.0 6.0 25 50 1.2 1.6 | 1.8 2.0 2.2 2.4 110 135 160 205 235 255 275 285 288 290 291 If,A EA, V What is the full-load speed of this motor?Select one: a. Full-load speed n = 1548 RPM b. Full-load speed n = 1938 RPM c. Full-load speed n = 1453 RPM d. None
Q23) A shunt generator supplies a 20KW load at 200V through cables of resistance, R = 100mΩ. If the field winding resistance ,Rf=50Ω and the armature resistance, Ra=40mΩ, i) Estimate terminal voltage across the load. ii) Calculate the emf generated in the armature.
a dc shunt generator supplies a load of 10kW at 250V calculate the induced emf,if the armature resistance is o.5ohm and the shunt field resistance is 100ohm
The following test data are taken from 60kW, eight pole, 400 V, 50 Hz, class C, junction IM.DC Test: RDC = 0.152Ω Idle test:VNL = 400 , V f = 50 Hz , INL = 30 A ,PNL = 3400 W Locked-rotor TestVBR = 80 , Vf = 12.5 Hz IBR = 120 A ,PBR = 6500 W a) Find the velocities of the stator and rotor magnetic field? b) Find the value of smax and Tmax? c) Input current I1 and Input power Pin? d) Air gap power PAG and Rotor copper losses PRCL? e) Ind. Mek. Power Pconv and Output power Pout? f) Tconv the generated moment, Tout the spindle moment, and the efficiency of the motor ɳ? g) Find the value of smax and Tmax? h) Find the circuit parameters? i) Draw the per phase equivalent circuit of this motor?
A 220 V, 21 A, 1000 rpm dc shunt motor has an armature resistance of 0.05 ohm and a ﬁeld resistance of 220 ohms. The magnetization curve for the machine is given by the following table:’ Field current (A) 0.2 0.4 0.6 0.8 1.0 1.2 1.4 EMF at1000 rpm (V) 50 100 150 190 219 235 245 Plot the speed-torque curve for the motor when: (a) no external resistances are included. (b) a resistance of 0.05 ohm is connected in series with the armature. (c) a resistance of 110 ohms is included in series with the ﬁeld winding. 3- The motor in Problem 1 draws an armature current of 21 A on full load -and runs at 1000 rpm. If a resistance of 0.5 ohm is inserted in series with armature, determine: (a) the speed at full load torque, (b) the speed at 60 per cent of full load torque, and (c) the ratio of starting torque to full load torque.
A 180-V, DC motor is connected as a cumulatively-compounded DC motor. Its characteristics are given below: RA = 0.10 2 Rs = 0.05 2 RF = 125 2 Radj = 100 2 NF = 1000 turns NSE= 10 turns IL, rated = 55 A Nm=1800 RPM This motor has compensating windings and interpoles. When the motor is rotating at 1680 RPM, 180 V supply, 52 A armature current, the rotational losses are 933 Watt. What is the efficiency of this motor? Select one: O a. % Efficiency = 74.5 % O b. % Efficiency = 84.4 % O c. None O d. % Efficiency = 94.2 %
A triangle connected, round rotor synchronous generator with Xs= 15 Ohm, Ra=0 works in parallel with a network with 400 V interphase voltage and gives only P= 62700 W active power. Find the amplitude of the induced internal electromotive force "Ef" and how many degrees the charge angle is. (It will be assumed that the generator is not overloaded, magnetically linear, no saturation, mechanical losses are neglected, and the armature internal resistance Ra is neglected.) (three digits after the comma.)
Determine the efficiency of 1500kVA, 2300V, 3phase, Y-connected alternator, which operates at rated output with a power factor of 80%. The DC armature resistance at 70°C between terminals is 0.08Ω. The field takes 70A at a 120V from the exciter equipment. Friction and windage loss are 15kW, iron loss is 35kW and stray load losses is 1.5kW. Assume the effective armature winding resistance is 1.5 times the DC value.
Find the speed and torque at the steady-state for the drive has the following parameters: Electric Motor: A 220 V, 13 A and Kϕ=2.5 (V. sec) DC separately excited motor has Ra= 0.8 Ω , and Rf=Rf= 10 Ω . Conveyors: TL=175 TL=175 N.m Find the steady-state operating point, the speed(N) and torque(T). Determine the steady-state for the equilibrium point.