A power system consists of $$300$$ buses out of which $$20$$ buses are generator buses, $$25$$ buses are the ones with reactive power support and $$15$$ buses are the 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 Newton-Raphson method. The size of the Newton-Raphson Jacobian matrix is

The bus impedance matrix of a $$4$$-bus power system is given by $$${Z_{bus}} = \left[ {\matrix{ {j0.3435} & {j0.2860} & {j0.2723} & {j0.277} \cr {j0.2860} & {j0.3408} & {j0.2586} & {j0.2414} \cr {j0.2723} & {j0.2586} & {j0.2791} & {j0.2209} \cr {j0.2277} & {j0.2414} & {j0.2209} & {j0.2791} \cr } } \right]$$$

A branch having an impedance of $$j0.2\Omega $$ is connected between bus $$2$$ and the reference. Then the values of $${Z_{22,new}}$$ and $${Z_{23,new}}$$ of the bus impedance matrix of the modified network are respectively

Choose two appropriate auxiliary components of a HVDC transmission system from the following
$$1.$$ D.C. line inductor
$$2.$$ A.C. line inductor
$$3.$$ Reactive power sources
$$4.$$ Distance relays on D.C. line
$$5.$$ Series capacitance of A.C. line