Q$3.$

$($a$)$ A main switch board is supplied from a $\frac{22}{0\mathrm{.}43}kV,2\mathrm{.}0$ MVA transformer with an impedance of $6\%.$ The impedance of LV cables to the main switchboard is $(0\mathrm{.}0006+j0\mathrm{.}0012).$ The fault level at the $22$ kV intake point is $800$ MVA. Calculate the fault current at the main switchboard. State major assumptions you made, if applicable.

$(8$ marks$)$

$($b$)$ Electric power distribution systems can be configured in various ways to efficiently deliver electricity to consumers. The choice of configuration depends on factors such as load requirements, geographical location, cost, reliability, maintainability, and future expansion plans. Three common configurations for power distribution systems are:

Radial configuration

Ring configuration

Mesh configuration

Briefly discuss three $(3)$ main features, three $(3)$ advantages, and three $(3)$ disadvantages for each of these configurations