A 3-phase, 4500 kVA, 13 kV, 50 Hz, 4-pole, star-connected synchronous generator has synchronous reactance of 8 ohm/phase and an armature resistance of 0.5 ohm/phase. With an assumption that the mechanical stray loss is 30 kW and power factor of 0.8 lagging, determine the followings: i) Stator current ii) Excitation voltage iii) Voltage regulation iv) Efficiency of the generator v) If the synchronous generator is delta connected and power factor is changed to 0.9 lagging, determine the maximum power supplied by the generator.

A 3-phase, 4500 kVA, 13 kV, 50 Hz, 4-pole, star-connected synchronous generator has synchronous reactance of 8 ohm/phase and an armature resistance of 0.5 ohm/phase. With an assumption that the mechanical stray loss is 30 kW and power factor of 0.8 lagging, determine the followings: i) Stator current ii) Excitation voltage iii) Voltage regulation iv) Efficiency of the generator v) If the synchronous generator is delta connected and power factor is changed to 0.9 lagging, determine the maximum power supplied by the generator.

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

Chapter12: Power System Controls

Section: Chapter Questions

Problem 12.11P

See similar textbooks

Similar questions

For Problem 3.18, the motor operates at full load, at 0.8 power factor leading, and at a terminal voltage of 10.45 kV. Determine (a) the voltage at bus 1, which is the generator bus, and (b) the generator and motor internal EMFs.
A 3 phase, star connected synchronous generator supplies current of 10A having phase angle of 20º lagging at 400V. Find the load angle and the components of armature current Id and Iq if Xd = 10 ohm and Xq = 6.5 ohm Assume armature resistances to be negligible
a) 3-phase star-connected synchronous generator supplies a current of 10A having phase angle of 20° lagging 400V (phase voltage). Given the direct and quadrature axis reactances as 10ohms and 6.5ohms respectively and neglecting armature resistance, Find: 1. The load angle 2 The direct and quadrature components of armature currents 3. Voltage regulation
QUESTION 1:- (a) A 4-pole, 3-phase, star-connected, 50 Hz synchronous generator, with a synchronous impedance of j24.5 Ω/phase and negligible resistance, delivers 5 MW of power to a 13.8 kV busbar. At this operating point, the excitation is equal to 1.8 p.u. Calculate the phase value of the generated emf (E) and hence calculate the electrical load angle, δ, at which the machine is operating. (b) Sketch a typical operating chart for a salient pole synchronous generator and on the chart identify the following; The Apparent Power limit, The field (excitation) limit, The Real Power limit, A line which represents a constant lagging power factor, The rotor angle for operation at any given point of operation, e.g. rated power and 0.9 power factor lag. (c) A Stamford HCI534F framesize generator has been selected for a stand-alone diesel-generation application. The generator is to operate at 400 V, 50 Hz, with the self-excited (SX) excitation scheme. Datasheet information can be…
a) With the aid of a diagram and phasor diagram, explain the double-reactance concept for salient-pole alternators. b) 3-phase star-connected synchronous generator supplies a current of 10A having phase angle of 20° lagging 400V (phase voltage). Given the direct and quadrature axis reactances as 10ohms and 6.5ohms respectively and neglecting armature resistance, Find: 1. The load angle 2 The direct and quadrature components of armature currents 3. Voltage regulation
In a three-phase, Y-connected, 750-kVA, 1732-V, synchronous generator afield current of 20 A at the rated speed produces a current of 300 A onshort circuit and a voltage of 1732 V on open circuit. The resistance betweenany two terminals of the generator is 0.8 R. Determine the synchronousreactance of the generator. The rotational loss is 20 kW. Using the per-unitsystem, determine the voltage regulation and the efficiency of the generatorwhen it delivers the rated load at its rated voltage and unity power factor.
A 3 phase 4MVA, 12 kV star connected synchronous generator has Zs= 0.8+J30 ohm. Using circle diagram only, find: 1. The output power developed at unity power factor with excitation equal to 1.25 of rated voltage. 2. The load angle and power factor if the generator supplies (1500 KW) at rated voltage and excitation lequal to (1.2) of rated voltage. 3. Repeat part (2) when .armature resistance is neglected
A 100KVA, 6.6 kV 3 PHASE star connected cylindrical pole synchronous generator has 20-ohm as synchronous reactance and the armature resistance is negligible and the generator is working at the full load and unity power factor then find the value of the induced emf voltage(line to line). Answer fast
electrical machines 3. 400 V 50 Hz, Y-connected, 6-pole synchronous generator per phase synchronous reactance 1.0 Ω at back power factor of 0.9 full load armature current 50 A, friction and wind losses 1.25 kW and core losses at 50Hz full load 1.0 kW and armature resistance and loss are neglected. The excitation current is adjusted so that the no-load output voltage is 400V. According to this; a) Calculate the rotation speed of the generator. b) find the terminal voltages at load with rated current at 0.8 back power factor and unit power factor . c) Calculate the voltage regulation of the generator for power coefficients of 0.8 back and 1.0.
A three phase, 50 Hz, 4800V, 6 pole Y-connected synchronous generator connected to an infinite bus (constant voltage at 4800V) and has synchronous reactance of 20Ω per phase and negligible armature resistance. The generator is delivering 1 MW at a power angle of 30 degrees.. Calculate the following:1. Output torque of the generator2. Excitation voltage Ea3. Armature current4. Power factor5. Reactive power delivered
A 70-MVA, 69.3-kV, three-phase round-rotor synchronous generator has a synchronous reactance of 14 ohm per phase and negligible armature resistance. 1) The generator is delivering rated power at 0.87 power factor lagging at the rated terminal voltage to an infinite bus bar (Fig. 1). Determine the magnitude of the generated emf per phase and the power angle δ. 2) The generator is delivering 53.5 MW to the bus bar at the rated voltage with its field current adjusted for a generated emf of 46 kV per phase. Determine the armature current and the power factor. Is the power factor is lagging or leading? 3) Given that the generator is operating at the excitation voltage of Part (1), determine the maximum steady-state power which the machine can deliver without losing synchronism. Find the armature current corresponding to this maximum power.
A synchronous generator of 100 MVA, 14.4kv, power factor 0.8 lagging, connected in Y, has a resistor in the armature negligible, a synchronous reactance of 1.0 per unit and a speed drop of 3%. The generator is connected in parallel with an infinite bus of 60hz and 14.4kv. a) What is the synchronous reactance of the generator in ohms? b) what is the internal voltage generated in nominal conditions? c) what is the frequency without load of the generator so that it delivers the nominal power of the system? d) Assume that the generator initially operates at nominal conditions. if it decreases 5% generated internal voltage Ea, what will be the new armature current Ia?