Q1// Explain the importance of load flow studies. Then illustrate the classification of Buses in load flow studies. Q2// Develop load flow equations suitable for solution by Gauss-Seidel method. Q3// The load flow data for a three-bus system is given in tables I and II. The voltage magnitude at bus 2 is to be maintained at 1.04 p.u. The maximum and minimum reactive power limits for bus 2 are 0.3 and 0.0 p.u. respectively. Taking bus 1 as the slack bus, determine the voltages of the various buses at the end of first iteration starting with a flat voltage profile for all buses except slack bus using Gauss-Seidel method with acceleration factors 1.6. Table I. Impedances for sample system Bus code Impedance 1-2 0.06 +0.18 1-3 0.02 +0.06 0.04 +0.12 Bus code Line changing admittance: Jaq 0.05 0.06 0.05 2-3 Table II. Assumed bus voltages, generation and loads Generation Lood Bus code Assumed voltages MW MV Ar MW MV Ar p.. P.. p.u. ри 1 1.06 0.0 0.0 0.0 0.0 0.00 2 10+ 0.0 0.2 0.0 0.0 0.00 1.0+ 0.0 0.0 0.0 0.6 0.25 Q4// A power system network consists of three elements 0-1, 1-2 and 2-0 of per unit impedances 0.2, 0.4 and 0.4 respectively. What is the bus impedance matrix? Q5// In the solution of load-flow equation, why Newton-Raphon (NR) method is superior to the Gauss- Seidal (GS) method. Q6// The per unit impedance of a circuit element is 0.15. If the base kV and base MVA are halved, then find the new value of the per unit impedance of the circuit element Q7// Two generators rated at 10 MVA, 11 KV and 15 MVA, 11 KV respectively are connected in parallel to a bus. The bus bars feed two motors rated 7.5 MVA and 10 MVA respectively. The rated voltage of the motors is 9 KV. The reactance of each generator is 12% and that of each motor is 15% on their own ratings. Assume 50 MVA, 10 KV base and draw the reactance diagram. 000 (M₁) 000 (M₂)