Chapter 3, Problem 3.23P

Figure 3.32 shows the oneline diagram of a three-phase power system. By selecting a common base of 100 MVA and 22 kV on the generator side, draw an impedance diagram showing all impedances including the load impedance in per-unit. The data are given a follows: $\begin{array}{l}G:\text{90MVA}\text{22kV}\text{x}\text{=}\text{0}\text{.18}\text{per}\text{unit}\\ T_1:\text{50MVA}\text{22/220kV}\text{x}\text{=}\text{0}\text{.10}\text{per}\text{unit}\\ T_2:\text{40MVA}\text{220/11kV}\text{x}\text{=}\text{0}\text{.06}\text{per}\text{unit}\\ T_3:\text{40MVA}\text{22/110kV}\text{x}\text{=}\text{0}\text{.064}\text{per}\text{unit}\\ T_4:\text{40MVA}\text{110/11kV}\text{x}\text{=}\text{0}\text{.08}\text{per}\text{unit}\\ M:\text{66}\text{.5MVA}\text{10}\text{.45kV}\text{x}\text{=}\text{0}\text{.185}\text{per}\text{unit}\end{array}$

Lines I and 2 have series reactance’s of 48.4 and $65.43\Omega$, respectively. At bus 4, the three-phase load absorbs 57 MVA at 10.45 kV and 0.6 power factor lagging.