A synchronous generator.connected to 1.0 per unit voltage infinite bus has 0.8 per unit reactance. If the current injected to the bus is one per unit at 0.6 power factor lagging. Evaluate no load voltage (E) and apparent power (S). If the excitation is adjusted such that reactive power Q=1 per unit for the same active power (P) and voltage (V), calculate the new values ofE, and load angle (8). 20U

A synchronous generator.connected to 1.0 per unit voltage infinite bus has 0.8 per unit reactance. If the current injected to the bus is one per unit at 0.6 power factor lagging. Evaluate no load voltage (E) and apparent power (S). If the excitation is adjusted such that reactive power Q=1 per unit for the same active power (P) and voltage (V), calculate the new values ofE, and load angle (8). 20U

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 12.9P

See similar textbooks

Similar questions

The amplitude of the sinusoidal symmetrical ac component of the three-phase short-circuit current of an unloaded synchronous machine decreases from a high initial value to a lower steady-state value, going periods through the stages of __________ and ________ periods.
A synchronous generator is rated 645 MVA, 24 kV, 0.9 pf lagging. It has a synchronous reactance 1.2 . The generator is feeding full load at 0.9 pf lagging at rated voltage. Calculate: (a) Excitation emf (E,) and power angle & (b) Reictive power drawn by the load Carry out calculations in pu form and convert the result to actual values.
What is voltage stability? How is reactive power linked with the voltage stability in the power system? Write down the effect of ‘Load Tap Changer (LTC)’ on voltage stability and analyze very briefly using P-U (nose) curve.
A generating system contains three 20 MW generating units each with a 3% FOR and one 45 MW unit with a 6% FOR. If the peak load for a 100 day period is 75 MW, what is the LOLE and EIR for this period? Assume the appropriate load characteristic is a straight line from the 100% to the 60% points.
The one-line diagram of a simple power system is shown in Figure below. The neutral of each generator is grounded through a current-limiting reactor of 0.25/3 per unit on a 100-MVA base. The system data expressed in per unit on a common 100-MVA base is tabulated below. The generators are running on no-load at their rated voltage and rated frequency with their emfs in phase. G Stark Item Base MVA Voltage Rating X' x² 20 kV 20 kV 20/220 kV 20/220 kV 100 0.05 0.15 0.15 0.10 0.10 220 kV 0.125 0.125 0.30 0.15 0.25 025 0.7125 0.15 100 100 0.15 0.05 0.10 0.10 0.10 100 0.10 100 100 Lu La 220 kV 0.15 220 kV 0.35 100 A balanced three-phase fault at bus 3 through a fault impedance Zf= jo.I per unit. The magnitude of the fault current in amperes in phase b for this fault is: Select one: A. 345.3 B. 820.1 C. 312500 3888888 产产

Two turbo alternators rated for 140 MW and 260 MW have gov ernor drop characteristics of 5% from no load to full load. They are connected in parallel to share a load of 250 MW. Determine the load shared by each machine suming free governing action.
Referring to the rated values of the components in Figure Q.2, draw the impedance diagram with all the marked reactances in p.u. If the motor M have input of 180 MW at 13.2 kV, and operate at unity power factor, determine the voltage in kV at the middle of the line. Choose the generator rating as base in generator circuit.
In a given system of base power of 250 MW, and bus 3 is taken as reference. The per-unit reactances are X12 = 0.2 p.u., X13 = X23 = 0. 1 p.u. The power flow in the system is given as: PF12 = 50 MW, PF13 = 150 MW, PF23 = 50 MW. Based on readings from 2 meters (not including M12 meter), M13 = 145 MW (not calibrated), and M23 = 50 MW (well calibrated), deduce the flow on line 1-2. Select one: O a. PF12 = - 47.5 MW. O b. None of these O c. PF12 = 67.5 MW. O d. PF12 = 47.5 MW. O e. PF12 =- 57.5 MW. O f. PF12 = 57 MW.
A 50HZ, synchronous generator is connected to infinite bus through a transmission line. The pu reactance of generator and transformer line are j0.4 and j0.2 respectively. The no load Voltage of generator is 1.2pu and infinite bus-lpu. Inertia constant is 4MJ/MVA. Determine frequency of natural oscillation if generator is loaded frequency to 50% ofP, Ka) 1.31 Hz, 1.09 Hz (c) 1.01 Hz, 1.09 Hz ubiun and 80% of P, and small disturbance is applied max max (b) 1.31 Hz, 1.29 Hz (d) 1.01 Hz, 1.29 Hz
The figure below shows the one-line diagram of a four- bus power system. The voltages, the scheduled real power and reactive powers, and the reactances of transmission lines are marked at this one line diagram (The voltages and reactances are in PU referred to 100 MW base. The active power P2 in MW is the last three digits (from right) of your registration number (i.e for the student that has a registration number 202112396, P2 =396). [10] Starting from an estimated voltage at bus 2, bus 3, and bus 4 equals V2 (0) = 1.15<0°, V3 = 1.15 < 0°, V4 1.1< 0°. 1- Specify the type of each bus and known & unknown quantities at each bus. 2- Find the elements of the second row of the admittance matrix (i.e. [Y21 Y22 Y23 Y24]). 3- Using Gauss-Siedal fınd the voltage at bus 2 after the first iteration. 4- Using Newton-Raphson, calculate: |- The value of real power (P2), at bus 2 after the first iteration. Il- The second element in the first row of the Jacobian matrix after the first iteration. 2 P2…
To improve power factor by static capacitor method. If the capacitance per phase is increases, then current taking from supply is Does not change Increases O Doubled O Decreases In synchronous condenser method to increase power factor, synchronous motor is act as capacitive (Capacitor) nature at O No load, rated excitation condition. Full load under excitation condition O No load, under excitation condition. No load, over excitation condition. 0S の ENG 10/C
A 600 KVA generator with X"a = 0.22 per unit is connected to a bus through a circuit breaker, as shown in the following figure. Connected through circuit breakers to the same bus are three synchronous motors rated 200 KVA, 2.5 KV, 1.0 power factor, with X"a = 0.15 per unit. The motors are operating at full load, unity power factor and rated voltage, with the load equally divided among the machines. (a) Find the rated symmetrical short-circuit current in Amperes, which must be interrupting breakers A and B for a fault at point P. Simplify the calculations by neglecting the Prefault current. M. GHA B