A 60 Hz, 33 kV, 3-phase alternator with earthed neutral has a reactance of 7 ohms per phase and is connected to a bus-bar through a circuit breaker. The distributed capacitance upto circuit breaker between phase and neutral in 0.03 uF. Determine (i) peak re-striking voltage across the contacts of the breaker (ii) frequency of oscillations

A 60 Hz, 33 kV, 3-phase alternator with earthed neutral has a reactance of 7 ohms per phase and is connected to a bus-bar through a circuit breaker. The distributed capacitance upto circuit breaker between phase and neutral in 0.03 uF. Determine (i) peak re-striking voltage across the contacts of the breaker (ii) frequency of oscillations

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

Chapter7: Symmetrical Faults

Section: Chapter Questions

Problem 7.21MCQ

See similar textbooks

Similar questions

Generate a conclusion on this following statements: Determine and analyze the voltage regulation characteristics of the alternator with resistive, capacitive, and inductive loading.
The step down DC chopper uses DC source voltage V(dc) = 200 V and resistive load impedance of 10 ohm. The duty cycle is 0.4 the voltage drop across the switch may be taken as zero, Calculate : (a) Average and RMS value of output voltage. (b) Average and RMS value of output current.
13. The transformer in a large welder provides single-phase ac output at 30 V, 50 Hz. An SCR bridge is used to control the welder. A large inductor helps to maintain a welding arc. a. What phase delay angle should be used to set an initial voltage of 25 Vac? b. The phase angle drops back once the arc has formed. What phase delay angle is needed for 8 Vdc output?
(iv) none of above 64. A 50 Hz, 11 kV, 3-phase alternator with earthed neutral has a reactance of 5 ohms per phase and is connected to a bus-bar through a circuit breaker. The distributed capacitance upto circuit breaker between phase and neutral is 0.01 µF. The peak re- striking voltage across the contacts of the breaker is
A three-phase 3300V. 50 Hz star-connected alternator has an effective resistance of 0.5 ohm/phase. A field current to of 30A produces full-load current of 180A on short- circit and a line to line emf of 1000V on open circit Determine(i) the power angle of the alternator when it delivers full-load at 0.8p.f(lag) (ii)the SCR of the alternator D
b) Explain the conditions of parallel connection of alternators and how these conditions are fulfilled.
A 45 – microfarad is connected to a 118 – volt 60 – cycle source. Calculate (a) the capacitive reactance, (b) the current, (c) the maximum power delivered to the capacitor or returned to the source, (d) the average power. Write equations for (e) the current and (f) the power.
a) A sinewave is having a frequency of 50 Hz and instantaneous voltage of 200 Volts at 1.2 milli seconds. Find: i) The maximum value of sinusoidal voltage waveform ? ii) The value of voltage at 1.8 milli seconds. b) An alternating voltage is given by v=100 sin(140 Ttt +0.25) volts. Find: (i) Peak to Peak Value of voltage ( (ii) Average Value of voltage (iii) Phase angle in degrees with respect to 100sin(140Ttt). (iv) The instantaneous value of voltage when t=0 (* (v) Draw the sine wave of 100sin(140 Ttt). (*
A three-phase, 4-pole, 1,500 rpm alternating having a double layer-windings with 18 turns per coil. The slots per pole per phase are 10 and the coil span is 22 slots. The spread phase is 60 degrees and the flux per pole is 0.0625 Weber. If the armature windings are wye connected. a) Determine the generated voltage per phase and the line to line voltages. b) If the alternator is delivering a three - phase load of 1,200KW at 0.8 lagging power factor what is the line current of the alternator
1. Impedance is the total opposition to an AC circuit caused by electric penalty tions, the tra capa multiple pacitive systema 62 Fundamentals of AC Electricity Questions for This C a. 1. Draw a diagram of an AC sine wave and identify its peak voltage and peak-to-peak voltage levels. b. 2. Explain the term frequency as it refers to AC electricity. c. 3. Discuss the difference between a load center and a fused disconnect. 2. WE wa 4. Explain how you would test for voltage in a fusible dis- connect on the line-side and load-side terminals. vi ci 5. Trace the path of a generated AC voltage from the generat- ing station where it is produced to the point where you would connect it to a machine in a factory. Be sure to iden- tify all the important parts of the system between the gen- eration station and the disconnect on the machine. a. be 3. True or False inductive reactance, capacitive reactance, and resistan 2. The units of impedance are
If the output voltage across the transformer secondary coil is Vm AC volt. a- Give a circuit to covert the Vm AC volt. to double Vm DC volt. b- Determine the voltage across each capacitor during the positive half cycle of the AC signal. c- Determine the voltage across each capacitor during the negative half cycle of the AC signal.
Armature reaction in an alternator affects generated voltage/phase Select one: O True O False