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- Power System Operation and Control - PSOC
- 2018
- PYQ
**Biju Patnaik University of Technology Rourkela Odisha - BPUT**- Electrical Engineering
- B.Tech
**3509 Views**- 33 Offline Downloads
- Uploaded 10 months ago

Registration No : Total Number of Pages : 02 B.Tech PCEL4401 7th Semester Back Examination 2018-19 POWER SYSTEM OPERATION AND CONTROL BRANCH : EEE, ELECTRICAL Time : 3 Hours Max Marks : 70 Q.CODE : E530 Answer Question No.1 which is compulsory and any FIVE from the rest. The figures in the right hand margin indicate marks. Q1 a) b) c) d) e) f) g) h) i) j) Q2 a) Answer the following questions : What will be the reactive power and bus voltage when the generator bus is treated as load bus? What do you understand by one-line diagram of the power system and explain its importance? A generator has a per unit value of 15% on a 50 MVA, 132 kV base. What would be the per unit value of the same on a 200 MVA, 66 kV base? Define steady state stability? How the elements of Jacobian matrix are computed? What is meant by Q-V control of power system? Why is the function of fly ball speed governor in load frequency control? What is the role of tie-line in multi-control-area system? The power generated by two plants are: P1 50 MW , P2 40 MW (2 x 10) If the loss coefficients are B11 0.001, B22 0.0025, and , B12 0.0005 , Calculate the power loss. An infinite bus of 1 pu is fed from a synchronous machine having E = 1.1 pu. If thetransfer reactance between them is 0.5 pu. Determine the steady state power limit. For the 3-bus system shown in Fig.1. all transmission lines have series impedance of 0.03 + j0.lpu and total shunt admittance of j0.02 pu. (i) Calculate YBus matrix. (ii) Write the power flow equations Slack Bus (2 + 3) 2 1 SD2 = 1.5 +j1.0 V1 = 1.05 <0˚ 3 | V3 |= 1.02 P3 = 0.6 Fig. 1 Q3 b) Obtain the voltage magnitudes and angles at bus 2 & 3 after first iteration using Gauss-Seidel algorithm. (5) a) Develop necessary equation and describe the load flow solution using GaussSeidel method? (5)

Q4 b) The terminal voltage of a star connected load consisting of three equal impedances of 2545 is 4.4 kV line to line. The impedance of each of the three lines connecting the load to a bus at a substation is Z L 2.2 85 . Find the line-to-line voltage at the substation bus. (5) a) Derive the solution of the economic load dispatch problem of a two-generator system with considering the transmission losses? Assume that the fuel input in Btu per hour for units 1 and 2 are given by (5) b) F1 5 P1 0.022 P 75 10 2 1 (5) 6 F2 8 P2 0.042 P22 95 106 The maximum and minimum loads on the units are 100 MW and 20 MW respectively.Determine the minimum cost of generation when the following load (Fig. 2.) is supplied. The cost of fuel is Rs. 2 per million Btu. 200 MW 100 MW 12 Q5 a) b) 100 MW 6 AM Fig. 2. 6 PM 12 What do you understand by load frequency mechanism? Explain in brief. Single area consists of two units with following parameters, Unit-1: 1250 MVA, R1 6% ( on machine base) (5) (5) Unit-2: 900 MVA, R2 4% ( on machine base) The units are sharing 1800 MW at nominal frequency of 50 Hz. Unit-1 supplies 1200 MW and unit-2 supplies 800 MW. The load is now increased by 250 MW. Find steady state frequency and generation of each unit if D=0. Q6 a) b) Q7 a) b) Q8 a) b) c) d) Explain the concept of control area. Also discuss the power frequency characteristic of an interconnected area. Derive the swing equation of a synchronous machine swinging against an infinite bus.Clearly state the assumptions in deducing the swing equation. (5) What do you mean by power system stability? A two-machine power system delivers a load of 25 MW at 0.8 p.f. lag and has adouble circuit. The system reactance is 150 percent on 100 MVA base. A sudden symmetrical line-to-ground fault occurs in one of the circuits which reduced the power supplied to 40% which is subsequently cleared by simultaneous action of the circuit breakers on both sides of the faulted line. Calculate in the electrical degrees the “critical clearing angle”. Assume that during fault conditions the system reactance attains such a value that the maximum power becomes 30% ofthe normal maximum value, when the faulty line is isolated the maximum power of the system becomes 60% of the normal maximum power. (2) (8) Write short answer on any TWO : Primary and secondary load frequency control Automatic voltage regulator Speed-Governing System Step-By-Step Solution of the Swing Curve (5) (5 x 2)

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