Repeat Problem 3.60, except keep the phase-shift angle fixed at 3.0 degrees while varying the LTC tap between 0.9 and 1.1. What tap value minimizes the real power losses?

Problem 3.60

PowerWorld Simulator case Problem 3_60 duplicates Example 3.13 except that a resistance term of 0.06 per unit has been added to the transformer and 0.05 per unit to the transmission line. Since the system is no longer lossless, a field showing the real power losses has also been added to the oneline. With the LTC tap fixed at 1.05, plot the real power losses as the phase shift angle is varied from -10 to +10 degrees. What value of phase shift minimizes the system losses?

Example 3.13

Two buses \(a b c\) and \(a^{\prime} b^{\prime} c^{\prime}\) are connected by two parallel lines L1 and L2 with positive-sequence series reactances \(X_{\mathrm{L} 1}=0.25\) and \(X_{\mathrm{L} 2}=0.20\) per unit. A regulating transformer is placed in series with line L1 at bus \(a^{\prime} b^{\prime} c^{\prime}\). Determine the \(2 \times 2\) bus admittance matrix when the regulating transformer.