Obtain the per-unit equivalent circuit for the following one-line diagram in Figure 1. Xine = 100 Q Zoad 0.9 + j0.20 50 MVA 11/66 kV X=j0.10 pu Vs 11 kV 50 MVA 66/11 kV X-j0.10 pu Figure 1 Take the MVA base of 100 MVA at the generator side and kV base of 11 kv for voltage base. Draw the per-unit impedance diagram showing all the per-unit values on the diagram. a) From your opinion, why per-unit representation is preferable when solving for power system network.

12. You plot the current-voltage characteristics of a new non-ohmic device, perform a curve fit, and discover the current as a function of voltage is given by the equation: I = (9Amp/volt")V² – (7Amp/volt) V (a). Perform calculations to find the slope of a line tangent to this curve when V = 4.15 volts. (b). Calculate the effective resistance of this device when V = 4.15 volts. This device is Non-Ohmic!