The bus admittance matrix and power flow 1

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EXERCISES FOR ELECTRIC POWER SYSTEMS COURSE ENERGY DEPARTMENT, Electrical section Class 7 The Bus admittance matrix and Power Flow Consider the following electrical network with Line /g1850/g3039 /g4670Ω//g1863/g1865 /g4671 /g1854/g3039 /g4670μS//g1863/g1865 /g4671 /g1838/g1857/g1866/g1859/g1872 /g1860 /g4670/g1863/g1865 /g4671 /g1848/g3041 /g4670/g1863/g1848 /g4671 L1 0.3 160 150 150 L2 0.3 160 37.5 150 L3 0.3 160 75 150 The synchronous generator G produces a real power of 450 MW and imposes a voltage of 157.50 kV at its busbars. The demand D absorbs an apparent power of /g1827/g3005/g3404 300 /g4670/g1839/g1848/g1827 /g4671 with lagging power factor of cos/g2030 /g3404 0.8944 . The External Grid is modeled as an infinite power generator and imposes at its busbars a voltage of 153 kV. Determine: 1. The bus admittance matrix a. using the incidence matrix (the graph representation of the network); b. by network inspection. 2. Neglecting the shunt elements of the electric lines( neglecting /g1854 /g3039): 2.1. identify the bus types for Power Flow (PF) computations; 2.2. choose the starting profile for the iterative process of PF; 2.3. write the PF system of equations; 2.4. solve the PF system of equations using the Gauss method, considering the tolerance equal to 0.001. 2.5. solve the PF system of equations using the Newton-Rhapson method, considering the tolerance equal to 0.001. NOTE : all the computations will be made in p.u. 1 2 3 Ext Grid L1 L2 L3 G D