Power is transferred from system $$A$$ to system $$B$$ by an $$HVDC$$ link as shown in the figure. If the voltage $${V_{AB}}$$ and $${V_{CD}}$$ are as indicated in the figure, and 1 > 0, then

For the power system shown in the figure below, the specifications of the components are the following:
$$G1: 25$$ $$kV,$$ $$100$$ $$MVA,$$ $$X=9$$%
$$G2: 25$$ $$kV,$$ $$100$$ $$MVA,$$ $$X=9$$%
$$T1: 25$$ $$kV/220$$ $$kV,$$ $$90$$ $$MVA,$$ $$X=12$$%
$$T2: 220$$ $$kV/ 25$$ $$kV,$$ $$90$$ $$MVA,$$ $$X=12$$%
$$Line$$ $$1: 220$$ $$kV,$$ $$X= 150$$ $$ohms$$

Choose $$25$$ $$kV$$ as the base voltage at the generator $$G1,$$ and $$200$$ $$MVA$$ as the $$MVA$$ base. The impedance diagram is

Consider a three-core, three phase, $$50$$ $$Hz$$, $$11$$ $$kV$$ cable whose conductors are denoted as $$R, Y$$ and $$B$$ in the figure. The inter-phase capacitance $$\left( {{C_1}} \right)$$ between each pair of conductors is $$0.2$$ $$\mu F$$ and the capacitance between each line conductor and the sheath is $$0.4$$ $$\mu F$$ . The per-phase charging current is

Consider a step voltage wave of magnitude $$1$$ pu travelling along a loss less transmission line that terminates in a reactor. The voltage magnitude across the reactor at the instant the travelling wave reaches the reactor is