protective relay. o uonRJado pn unM DAIRUIDJO0O SI b) A fault occurs at bus 3 of the network shown in Figure Q3. Pre-fault nodal voltages throughout the network are of 1 p.u. and the impedance of the electric arc is neglected. Sequence impedance parameters of the generator, transmission lines, and transfommer are given in Figure Q3, where X and Y are the last two digits of your student number. Xoy 10.1Xp.u. Xa-/0.2Y p.u. V,- 120° p.u. V,- 120° p.u. V,-120 p.u. Kan-/0.1X p.u. Xe" j0.1X p.u. X 0.IY p.u. K 025 p.u. IA2A 025 p.a. 3 M" J0.3 p.u. Xay J0.1X p.u. Xaey" J0.1X p.u. X /0.05 p.u. 0- Aray- J0.1Y p.u. Xo,0.IY p.u. 0. Figure Q3. Circuit for problem 3b). For example, if your student number is c1700123, then: jXac1) j0.12 p.u., Xa)-/0.12 p.u., and jXaco) = /0.13 p.u. (0) Assuming a balanced excitation, draw the positive, negative and zero sequence Thévenin equivalent circuits as seen from bus 3. (u) Determine the positive sequence fault current for the case when a three- phase-to-ground fault occurs at bus 3 of the network. () Determine the short-circuit fault current for the case when a one-phase- to-ground fault occurs at bus 3. (iv) Determine the short-circuit fault current for the case when a phase-to- phase fault occurs at bus 3.