A synchronous motor with delta conductive coils is fed from a 480V source. Its synchronous impedance is 102, the product winding resistance is neglected, and the ferrous losses and friction losses are neglected as well. Find the following: A) If it is running a 400hp load at a power factor of 0.85 lead, find the value and angle of E, and Ip B) If the field current increases by 10%, explain the motor behavior using the vector diagram. (C) Find the values of E, I, and I after increasing the load (D) Calculate the power factor after increasing the load.

A synchronous motor with delta conductive coils is fed from a 480V source. Its synchronous impedance is 102, the product winding resistance is neglected, and the ferrous losses and friction losses are neglected as well. Find the following: A) If it is running a 400hp load at a power factor of 0.85 lead, find the value and angle of E, and Ip B) If the field current increases by 10%, explain the motor behavior using the vector diagram. (C) Find the values of E, I, and I after increasing the load (D) Calculate the power factor after increasing the load.

Electricity for Refrigeration, Heating, and Air Conditioning (MindTap Course List)

10th Edition

ISBN:9781337399128

Author:Russell E. Smith

Publisher:Russell E. Smith

Chapter8: Basic Electric Motors

Section: Chapter Questions

Problem 28RQ: What are the advantages and disadvantages of using the following types of motors? shaded-pole...

See similar textbooks

Similar questions

The input to an industrial plant is 1,440 kw at a power factor of 0.6 lagging. It is desired to connect a synchronous motor that operates at a leading power factor of 0.8 to the power mains and have it correct the over-all power factor to 0.9. (A) What should be the POWER INPUT to the synchronous motor? (B) Calculate the HORSEPOWER OUTPUT of a synchronous motor but this time, it's operating at a leading power factor of 0.8 and an efficiency of 87.4percent that will correct the over-all power factor to unity.
Three-phase 60Hz, 8-Pole 460v, star-connected, 100kW asynchronous motor has single-phase equivalent circuit parameters in the picture. a) Find the Thevenin equivalent circuit and its parameters. b)Find development torque, maximum torque. find
A 400V, 50Hz, 6-pole 3-phase asynchronous motor rotates 20Nm of constant load torque at 950rpm. If it is desired to rotate this load at 750 rpm mechanical speed;a) The synchronous speed of the motor,b) Supply frequency,c) Find the value of the supply voltage between phases?Note: The motor will be driven with V/F sbt because the load torque does not change.
Find the steady-state torque–speed relation for a compound-wound motor. The following parameters are given: Rf1=Rf2=10Ω, Ra= 2 5Ω, Rf=20Ω, and k= 1 N.m/A . Assume that the supply voltage is 115 V. Plot the steady-state torque–speed curve.( need only handwritten solution .otherwise downvote.)
3) The conversion ratio of an asynchronous motor with 415 V, 3-phase, 60Hz, 6-pole, Y-connected rotor winding is a = N1 / N2 = 1.5,Parameter values per phase transferred to the stator are given below. a) For the case where slip s = 0.05, calculate the stator current, the torque generated in the motor, with the rotor circuit voltageCalculate the frequency.b) Subtract the Thevenin equivalent.c) The rotor stays stuck while the motor is running under load. Find the rotor current reflected to the stator at this instant.d) Find the maximum torque the motor can produce.e) It is required that the engine initially develops with maximum torque. For this, externalFind the value of the resistance transferred to the stator
a 3-phase, 220-v, 50-hz, 1500 r.p.m., mesh-connected synchronous motor has a synchronous impedance of 4 ohm per phase. it receives an input line current of 30a at a leading power factor of 0.8. find the line value of the induced e.m.f. and the load angle expressed in mechanical degrees. if the mechanical load is thrown off without change of excitation, determine the magnitude of the current under the new conditions. neglect losses.
A single-phase, 120 V, 60 Hz, four-pole, split-phase induction motor has the following standstill impedances:Main winding: Zm =5+j6.25Auxiliary winding: Za =8+j6a) Determine the value of capacitance to be added in series with the auxiliary winding to obtainmaximum starting torque.b) Compare the starting torques and starting current with and without the added capacitance in theauxiliary winding circuit when operated from a 120V, 60Hz supply
At standstill condition, the outer impedance of the outer cage of the double cage induction motor=(0.3+j0.40)ohm and the inner cage is (0.1+j1.5)ohm. Neglect the stator impedance. Find the ratio of the output to input current and the ratio of the output torqu to the inout torque.
A certain six-pole 440-V-rms 60-Hz three-phase delta-connected induction motor has Rs=0.08 ΩRr′=0.06 Ω Xs=0.20 ΩXr′=0.15 Ω Xm=7.5 Ω Neglecting the rotational losses, find the no-load speed, line current, and power factor for the motor.
A 440-V, 60-Hz, 2-pole, Y-connected, three-phase induction motor has the following parameters in ohms/phase: R1 = 0.3, X1 = 0.9, R2 = 0.6, X2 = 0.9, Rc = 150, Xm = 60. If the rotational loss is 4% of the powerdeveloped, determine the efficiency of the motor when it runs at 4% slip.
A 25-hp three-phase induction motor operates for a 440-Vrms (line-to-line) three phase source and draws a line current of 35 A rms at a power factor of 83 percent lagging under rated full load conditions. The full load speed is 1750 rpm. Under no load conditions the speed is 1797 rpm and the line current is 6.5 A rms at a power factor of 30 percent lagging. Find the power loss and efficiency with full load, the input power with no load and the speed regulation.
A three phase, 220V, 50Hz, rpm mesh connected synchronous motor has a synchronous reactance of 4 ohms per phase, it recieves an input line current of 30A at a leading power factor of 0.8. find the line value of induced emf and the torque angle expressed in mechanical degree by use of phasor diagram