Problem 1 Stator of 3-phase machine is excited by a current source as follows: I, lags Ia by 120 degrees and Ie lags I, by 120 degrees. Three-currents excite their respective windings on stator as shown in the figure. For Ia = -Im for 0 < 0 < 7 Ia Im for 7 < 0 < 27 (a) Draw Ia, Ib, Ic. (b) Find Bnet- (c) Explain significance of Bnet in terms of rotation speed and rotation direction.

Problem 1 Stator of 3-phase machine is excited by a current source as follows: I, lags Ia by 120 degrees and Ie lags I, by 120 degrees. Three-currents excite their respective windings on stator as shown in the figure. For Ia = -Im for 0 < 0 < 7 Ia Im for 7 < 0 < 27 (a) Draw Ia, Ib, Ic. (b) Find Bnet- (c) Explain significance of Bnet in terms of rotation speed and rotation direction.

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter2: Fundamentals

Section: Chapter Questions

Problem 2.41P

See similar textbooks

Similar questions

A single-phase, 120V(rms),60Hz source supplies power to a series R-L circuit consisting of R=10 and L=40mH. (a) Determine the power factor of the circuit and state whether it is lagging or leading. (b) Determine the real and reactive power absorbed by the load. (c) Calculate the peak magnetic energy Wint stored in the inductor by using the expression Wint=L(Irms)2 and check whether the reactive power Q=Wint is satisfied. (Note: The instantaneous magnetic energy storage fluctuates between zero and the peak energy. This energy must be sent twice each cycle to the load from the source by means of reactive power flows.)
The direct electrical connection of the windings allows transient over voltages to pass through the auto transfonner more easily, and that is an important disadvantage of the autotransformer. (a) True (b) False
in distribution transformers; What is 30 degrees phase shift in delta-star connection? What are the disadvantages? (can you explain with drawing?)
L-type equivalent circuit and parameters for a continuous sinusoidal phase of a 5.5 kW, 1450 rpm, line voltage 220 V and frequency 50 Hz star-connected 3-phase ASM, ignoring core (iron) losses given as follows: R1=0.21 Ohm, R2=0.18 Ohm, X1=X2=0.66 Ohm and Xm=9.9 Ohm How many times the rated current will the inrush current be when the ASM is started directly?
a shunt generator supplies a load of 5,500w at 110v through a pair of feeder conductors having a resistance of 0.02 ohm each. the armature, shunt field resistances are 0.15 ohm and 50 ohms respectively, find the emf generated.
please explain the operating principle of single phase 2S-2P PMSM based on 3D design illustration.
(use 2-decimal digits for solutions) A synchronous generator runs at 250 rpm and generates at 50-Hz. There are 216slots, each containing 5 conductors arranged in a full-pitched winding for 3-phasestar connection. All the conductors of each phase are in series and the flux perpole at no-load sinusoidally distributed over the pole pitch is 30 mWb. Find the emfinduced in each phase winding and the terminal voltage.
A polyphase system is generated by______? a.Both a and c b.Having two or more generator windings separated by equal electrical angle c.Having generator windings at equal distances d.None of these
Sketch the complete per-phase equivalent circuit of a symmetrical non-salient pole three-phase synchronous generator, including the field winding circuit. Your figure should include the synchronous reactance Xs, explain its relation to Xar and Xl. In addition, explain/describe the rest of the different elements of this equivalent circuit.
A Turgo type hydro-electric plant uses a 92% efficiency generator to produce its rated output of 32.5 MW. It was observed during its operation that the mechanical loss is 4.25 MW. Also, from the penstock down to the turbine, 14.3% hydraulic head loss and 8.9% leakage loss occurs which are equally distributed and based on the parameters at the dam. The average elevation from the headrace to the jet centerline is 40 m and from the tailrace to the jet centerline is 4.5 m. compute the following: a. Power by the turbine, kW b. Volume flow rate at the source, m3/s c. Power by the jet, kW d. Mechanical Efficiency, %
Suppose two generators supplying a load. Generator-1 has a no-load frequency of 61.5 Hz and a slopesp1 of 1 MW/Hz. Generator-2 has a no-load frequency of 62 Hz and a slope sp2 of 1MW/Hz. The twogenerators are supplying a real load totaling 2.5 MW at 0.8 PF lagging. Draw the resulting systempower-frequency or house-diagrams. Determine (a) at what frequency is the system operating, andhow much power is supplied by each of the generators? (b) if an additional 0.75-MW load wereattached to this power system. What would the new system frequency be, and how much powerwould the each generator supply now? (c) with the system in the configuration described in part (b),what will the system frequency and generators power be if the governor set points on generator-1 areincreased by 0.5 Hz?
In a Three-phase alternator, a given field current produces an armature current of 250 A on short-circuit and a generated e.m.f. of 1500 V on open-circuit. Calculate the terminal p.d. when a load of 250 A at 6.6 kV and 0.8 p.f. lagging is switched off. Calculate also the regulation of the alternator at the given load. Subject: Electrical engineering