103 年 - 103 國立中山大學_碩士班招生考試_電機系(丁組)：電力工程#110072　

2. Calculate the geometric mean radius of conductors shown in Fig. 2 in terms of the radius r of an individual strand. (10%)

4. The impedance matrix () of a power system is
  
Calculate the short-circuit current for a three-phase fault occurred in bus 2 and determine the bus voltages during the fault (15%).

5. Derive the solution for the following economic dispatch problem by Lagrangian multiplier (15%)
   

6.Assume that the impedances for zero-sequence, positive-sequence and negative-sequence networks are Z₀, Z₁ and Z₂ , respectively. Derive the formulas for I₀, I₁ , I₂, and Ia and draw the interconnected sequence networks for a single line-to-ground fault as shown in Fig. 3 (20%)