Power Systems Objective Questions & Answers – Set 8
Power Systems Objective Questions & Answers
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Power system network has a total power of 5000 MW at 50 Hz supplying to the different consumers. Frequency is varying at 1.5% per change of 2% load. Assume R =0.004 Hz/MW. Find the steady state frequency deviation if a sudden loss of 200 MW occur due to tripping of one of the transmission line?
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The advantage of hydroelectric power station over thermal power station is
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A 200 MW capacity generator has a speed regulation of 4% for a frequency drop of 0.05 Hz. Find the power input supplied by the turbine for maintaining constant frequency?
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In load flow studies PV bus is treated as PQ bus when
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A 200 MVA alternator operated at no load at frequency of 50 Hz, it has inertia constant of 5 MWsec/MVA and governing system has a time delay of 0.6 sec. If the load of 50 MW is suddenly applied then find the frequency deviation during this time?
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Two generating stations delivering a powers of P_{1} = 150 MW, P_{2} =100 MW and the B coefficients are B_{11} = 0.005, B_{22} = 0.002, B_{12}=B_{21}= 0.001. Find the transmission line losses?
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A power system consists of 300 buses out of which 20 buses are generator buses, 25 buses are the ones with reactive power support buses and 15 buses are ones with fixed shunt capacitors. All the other buses are load buses. It is proposed to perform a load flow analysis for the system using NewtonRaphson Jacobian matrix is
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If the penalty factor of a plant is unity, its incremental transmission loss is
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In order to have lower cost of power generaion
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The power generated by two plants are; P_{1} = 50 MW, P_{2} = 40 MW. If the loss coefficients are B_{11} = 0.001, B_{22} = 0.0025 and B_{12} = 0.0005, then power loss will be
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The equation of area control error(ACE) is
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A 100 MVA alternator operating at full load at 50 Hz. H = 4 MWsec/MVA, T_{d} = 0.5 sec. One of the transmission line is tripped. So that output of generator is reduced to 70 MW. Find the frequency deviation during this time?
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In which of the following frequency control method tie line may be overloaded?
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Normally Z bus matrix is a
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The economics of power plant is greatly influenced by
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Length of short transmission line is up to
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A sort line with R/X ratio 1, the zero regulation is obtained when the power factor of the load is
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Units of incremental cost is
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The receiving end voltage for a long line under no load condition is
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A load centre is at an equidistant from the two thermal generating stations G_{1} and G_{2}. The fuel cost characteristics of the generating stations are given by F_{1} = a + bP_{1} + cPÂ²_{1} F_{2} = a + b P_{2} + 2cPÂ²_{2} Where P_{1} and P_{2} are the generation in MW of G_{1} and G_{2}, respectively. For most economic generation to meet 300 MW of load, P_{1} and P_{2} respectively, are
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If, for a given alternator in economic operation mode, the incremental cost is given by (0.012 P + 8) Rs/MWh, dP_{L}/dP = 0.2 and plant Î» = 25, then power generation is
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A lossless power system has to serve a load of 250 MW. There are two generators(G_{1} and G_{2}) in the system with cost curves C_{1} and C_{2} respectively defined as follows: C_{1} = P_{G1}+0.055PÂ²_{G1} C_{C2} = 3 P_{G2} + 0.03 PÂ²_{G2} Where P_{G1} and P_{G2} are the MW injections from generators G_{1} and G_{2} respectively. Thus, the minimum cost dispatch will be
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Which of the following is/are base load plants?
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Radio interference occur in telecommunication line due to
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The Y bus matrix of 100 bus interconnected system is 90% sparse. Hence the number of transmission lines in the system must be
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The Gauss Seidel load flow method has following disadvantages. Which of the following statement is wrong?
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Incremental cost of two generators I_{c1} = 0.2 P_{1}+60, I_{c2} = 0.3 P_{2}+40 and the ratings of the generator are 150 and 250 MW. Find the load sharing of each generator for a load of 200 MW?
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The incremental fuel costs for two generating units G_{1} and G_{2} are given by I_{c1} = 25 + 0.2 P_{G1} and I_{c2} = 32 + 0.2 P_{G2}, where P_{G1} and P_{G2} are real powers generated by the units. The economic allocation for a total load of 250 MW, neglecting transmission loss, is given by
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In a two plant system, the load is connected to plant number 2. The loss coefficients are
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As the frequency of the system is increased, the charging MVAR