Please use exact methods and not approximations!
Please use exact methods and not approximations! 7.15. A three-phase, 460 V, 60 Hz, 1760 rpm, wound-rotor induction mot...
A 3-phase, 460 V, 1740 rpm, 60 Hz, 4-pole wound-rotor induction motor has the following parameters per phase: R1 = 0.25 Ω, ' 2R = 0.2Ω, ' 1 2 X = X = 0.5Ω, 30 m X = Ω. The rotational losses are 1700 W. With the rotor terminals short-circuited, find: 1. at starting: • current when started direct on full voltage, • a torque 2. at full load: • slip • current • ratio of starting current to full-load...
Consider a 50 kW, 3-phase, 380 V line-to-line, 50 Hz, 6 pole Y-connected wound-rotor induction motor. The stator winding ac resistance is 0.1 Ω/phase. The effective stator-to-rotor turns ratio is 2. The exciting branch is negligible. It is found that when an external resistor of 0.09 Ω/phase is connected to the rotor terminals maximum starting torque of 1150 Nm is obtained. a. Compute the internal mechanical power and the internal torque developed by this motor when it drives a load...
A 3 phase, 440 V, 6 pole, 970 rpm, 50 Hz, Y-connected induction motor has the following parameters referred to the stator Rs = 0.2 Ω, Rr'一0.15 Ω, xs-x-= 0.4 Ω The stator to rotor turns ratio is 3.5 The motor speed is controled by the Static Scherbius Drive. The drive is designed for a speed range of 30% below the synchronous speed. The maximum value of firing angle is 170'. Calculate (i) Turns ratio of the transformer (ii) Torque...
3c) Induction Machine Analysis [ 8 marks ] A 415 V, 50 Hz, 1450 rpm, three-phase, star-connected induction machine has the following equivalent circuit parameters (referred to the stator winding where appropriate) stator resistance R 0.3 ohms, rotor resistance R2 0.2 ohms stator leakage reactance X 2 ohms, rotor leakage reactance X2' 2 ohms magnetising reactance XM 50 ohms, core loss resistance Rc 200 ohms In your calculations, you should use = the simplified equivalent circuit i) Find the number...
-23 An 8-pole, 230-V, 60-Hz, A-connected, three-phase induction motor has a rotor impedance of 0.025 + 0.112/phase. The stator winding impedance is negligible. Determine (a) the speed at which the motor develops the maximum torque, (b) the maximum torque of the motor, and (c) the start- ing torque as a percentage of maximum torque. What additional resistance must be inserted in the rotor circuit to make the starting torque equal to 75% of the maximum torque?
. A 460-V 460-V, 25-hp, 60-Hz, six-pole, Y-connected induction motor has the following impedanc ohms per phase referred to the stator circuit. Ri= 0.212 R2 = 0.282 X1 = 1.055 12 X2 = 1.055 22 XM = 33.9 W The total rotational losses are 1100 W and are assumed to be constant. The core loss is lumped with the rotational losses. For a rotor slip of 4% at the rated voltage and rated frequency, a) The input power b) Peony...
The three-phase wye-connected induction motor nameplate gives the following information: 400 V, 1755 rpm, 60 Hz. Rotor speed at no-load is 1799 rpm. At rated voltage and frequency motor core losses are 400 W. At rated rotor speed, mechanical losses are 400 W. The available parameters of the motor conventional equivalent circuit (6-parameters IEEE model) are: R1 = 0.2 Ω, R’2 = 0.2 Ω, X1 = 0.5 Ω, X’2 = 0.2 Ω and Xφ = 20.0 Ω. In all calculations,...
A 500 hp, three-phase, 2200 V, 60 Hz, 12-pole, Y-connected, wound-rotor induction motor has the following parameters: 5.9 0.225 Ω x, R, R',-0.235 Ω X, 31.8 Ω R""-780 Ω 1.43 Ω Calculate the following: a. Slip at maximum torque b. Input current and power factor at maximum torque c. Maximum torque d. Resistance that must be added to the rotor windings (per phase) to achieve maximum torque at starting
5. A 208-V four-pole 60-Hz Y-connected wound-rotor induction motor is rated at 30 hp. Its equivalent circuit components are R=0.100 Ry=0.070. X - 10.00 R = 250 X; -0.2100 X=0.21002 Praw=500 W P =0.5% of input at full load For a slip of 0.05, find (a) The line current (b) The induced voltage in the rotor (c) The stator power factor (d) The rotor power factor (e) The rotor frequency (f) The stator copper losses (g) The core loss (h)...
Question # 2(25 points) A three phase, 200 hp, 2400 V, 60 Hz, 4 pole, Y connected synchronous motor has a reactance of 12 Ω phase and a negligible armature resistance. The motor draws 150 KW at a power angle of-18 Determine a) The synchronous speed of the motor in rpm. (3 points) b) The excitation voltage E. (5 points) c) The line current. (5 points) d) The motor power factor. (3 points) e) The pull-out torque (maximum torque). (3...