Power Systems T...

A power flow problem is solved using Newton-Raphson power flow in polar coordinate. The Jacobian size is 50 × 50. There is one slack bus in the system. The number of PV buses is 4. The number of PQ buses is

Which of the following has a problem in convergence for a system with long radial lines?

A 500 × 500 bus admittance matrix for an electric power system 4000 non-zero elements the minimum number of branches in this system are –

A 3ϕ SC occurs at BUS – 4. The SC current flowing between buses 1 and 2 is___

Assume that the pre fault voltages at all the buses 1.0 Pu.

\({Z_{bus}} = j\left[ {\begin{array}{*{20}{c}} {0.15}&{0.08}&{\begin{array}{*{20}{c}} {0.04}&{0.07} \end{array}}\\ {\begin{array}{*{20}{c}} {0.08}\\ {\begin{array}{*{20}{c}} {0.04}\\ {0.07} \end{array}} \end{array}}&{\begin{array}{*{20}{c}} {0.15}\\ {\begin{array}{*{20}{c}} {0.06}\\ {0.09} \end{array}} \end{array}}&{\begin{array}{*{20}{c}} {\begin{array}{*{20}{c}} {0.06}\\ {\begin{array}{*{20}{c}} {0.13}\\ {0.05} \end{array}} \end{array}}&{\begin{array}{*{20}{c}} {0.09}\\ {\begin{array}{*{20}{c}} {0.05}\\ {0.12} \end{array}} \end{array}} \end{array}} \end{array}} \right]\)

The bus impedance matrix of a 4 – bus power system is given by

\({Z_{bus}} = \left[ {\begin{array}{*{20}{c}}{j0.3435}&{j0.2860}&{j0.2723}&{j0.2277}\\{j0.2860}&{j0.3408}&{j0.2586}&{j0.2414}\\{j0.2723}&{j0.2586}&{j0.2791}&{j0.2209}\\{j0.2277}&{j0.2414}&{j0.2209}&{j0.2791}\end{array}} \right]\)

A branch having an impedance of j 0.2 Ω is connected between bus 2 and the reference Then the values of Z₂₂,new and Z₂₃,new of the bus impedance matrix of the modified network are respectively.