Fault current, voltage in bus #$2$ and currents in the lines for bolted SLGF$,$DLSG$,$LLF in bus #$1$ of Figure $9\mathrm{.}3($no load $($Vpre $=1\mathrm{.}05$pu$)$

Reactances of a solidly grounded Y$,$ generator rated $100$MVA $20$kV are xd$=$ x$1=$ x$2=20\%$ and x$0=5\%.$ The generator is connected to a ungrounded Y$-$ transformer rated $100$MVA $20$kV $230$kV with a nameplate reactance of $10\%.$ The terminal voltage of the unloaded generator is $23$kV when

a$)$ a SLGF $($ZF $=$ j$5)$occurs in the open circuit, high voltage terminals of the transformer.$$ Please find, sub transient currents in all phases $($ in KA$)$ and the neutral conductor of the generator.

b$)$ a bolted line to line fault occurs in the open circuit, high voltage terminals of the transformer.$$ Please find, sub transient fault current and currents in all phases at the high voltage side of the transformer $($kA$).$

c$)$ a bolted double line to ground fault occurs in the open circuit, high voltage terminals of the transformer.$$ Please find the sub transient fault current and the fault line to neutral voltajes$($pu$)$ at the generator terminals.

d$)$ Repeat with all faults on bars $3$ and $4($#$3$ HVT T$1$ and #$4$ HVT T$2)$