A 72-kVA, 208-V, Y -connected, three-phase synchronous generator delivers the rated load at 0.866 pflagging. The armature winding resistance is 20 mΩ/phase. The core loss is 800 W. The friction and the windageloss is 350 W. The field winding is connected across a 120-V dc source and the field current is 5.5 A. Calculate the efficiency of the generator

A 72-kVA, 208-V, Y -connected, three-phase synchronous generator delivers the rated load at 0.866 pflagging. The armature winding resistance is 20 mΩ/phase. The core loss is 800 W. The friction and the windageloss is 350 W. The field winding is connected across a 120-V dc source and the field current is 5.5 A. Calculate the efficiency of the generator

Electric Motor Control

10th Edition

ISBN:9781133702818

Author:Herman

Publisher:Herman

Chapter39: Synchronous Motor Operation

Section: Chapter Questions

Problem 14SQ: Induction motors and welding transformers require magnetizing current, which causes a. lagging power...

See similar textbooks

Similar questions

AC Machinery Fundamentals A three-phase delta-connected six-pole winding is installed in 36 slots on a stator. There are 150 turns of wire in each slot of the windings. All coils in each phase are connected in series. The flux per pole in the machine is 0.060 Wb, and the speed of rotation of the magnetic field is 1000 r/min. What are the resulting phase and terminal voltages?
A 6 pole DC lap wound generator has 41 armature conductors with flux per pole is 23 mWb and the e.m.f generated is 80 V, then the speed of the machine is O 0.74 rps O 84.84 rps O 7.43 rps 84.84 rps
There are 160 slots in a 3-phase, 8-pole, 50 Hz., star connected alternator. There are 4 conductors in each slot and all the conductors in a phase are connected in series. Coil span is 150° electrical and the flux per pole is 0.08 Weber sinusoidally distributed. Calculate the emf induced per phase.
A 4 pole dc generator with duplex wave winding has 48 slots and four elements per slot. The flux perpole is 2.5 x 10 Maxwells and the speed of the prime mover is 30 rpm. What is the average generatedarmature voltage? Neglecting brush drop.
A dc 4 pole lap wound generator is running at 1000 rpm having 1200 conductors and flux density is 10 mwb. find the generated emf * O 10 V O 200 V O 100 V O 20 V
A 6-pole ,3 phase , 60 cycle alternator has 12 slots per pole and four conductor per slot. The winding is 5/6 pitch. There are 2,500,000 Maxwell ( 0.025 weber ) entering the armature from each north pole, and this flux sinusoidally distributed along the air gap. The armature coils are all connected in series , The winding is wye connected. Determine the open circuit emf of the alternator.
A four-pole three-phase 50 hertz, star connected AC generator has 12 stator slots. There are 4conductors per slot and a sinusoidally distributed flux per pole of 36mWb. Find the terminal voltageon open circuit. If the coil span factor is 0.85 lagging.
The armature of a two-pole generator is rotating at 3600 r/min. The armature has a simplex lap winding with a total of 1504 conductors. Determine the generated voltage when the flux per pole is 600,000 x 10-8 Wb. 5.5
A 2300V, 1000 kVA, 0.8 lagging power factor, two-pole, 60HZ, Wye-connected, synchronous generator has a synchronous reactance of 1.1 ohms and an armature resistance of 0.15 ohms. Its losses due to friction and friction with the air are 24 kW and its core losses are 18 kW. The field circuit has a dc voltage of 200v and a maximum of 10A. The field circuit current is adjustable in the range of 20 to 200 ohms.The magnetization curve of this generator is shown in the figure below.a) How much field current is required for Vt to equal 2300V when the generator is running without load?b) What is the voltage generated intermittently by this machine at nominal conditions?c) How much field current is needed to make the voltage at the terminals Vt=2300V when the generator works in nominal conditions?d) How much power and torque should the prime mover of the generator be able to supply?
Full solutions for the question with explanation
D2. When a generator's full-load output voltage is the same as its no-load output voltage it is said to be a) under-compounded b) flat-compounded c) over-compounded d) none of the above D3. The output of an overcompounded DC generator can be lowered by use of a a) rheostat connected in series with the series field b) rheostat connected in parallel with the series field c) rheostat connected in parallel with the shunt field d) none of the above D4. When might it be desirable to use an overcompounded generator? a) never b) always c) to compensate for line loss d) when you need a higher no-load voltage than your full-load voltage
Figure 1 shows an electric generator with 3 rotor windings as marked by a-1, b-2 and c-3. A permanent magnet is placed in the middle of the rotor with the rotational direction. The 3 rotor windings are connected through line to the three identical load resistors R₁, R₂ and R3 in Wye connection. The resulting currents in each line are la, lb and Ic. Design the generator-line-load connections, and propose the methodologies to construct 3-phase 3-wire connection. Use a diagram to justify your answers. D (0 N $1 Figure 1