The zero$-,$ positive$-,$ and negative$-$sequence bus impedance matrices for a three$-$bus three$-$

phase power system are:

$0=[$

$0\mathrm{.}1000$

$00\mathrm{.}200$

$000\mathrm{.}10$

$]$ per unit

$1=2=[$

$0\mathrm{.}120\mathrm{.}080\mathrm{.}04$

$0\mathrm{.}080\mathrm{.}120\mathrm{.}06$

$0\mathrm{.}040\mathrm{.}060\mathrm{.}08$

$]$ per unit

Determine the per$-$unit fault current and per$-$unit voltage at bus $2$ for:

a$)$ A bolted three$-$phase fault at bus $1.$

b$)$ A bolted single line$-$to$-$ground fault at bus $1.$

c$)$ A bolted line$-$to$-$line fault at bus $1.$

d$)$ A bolted double line$-$to$-$ground fault at bus $1$