Consider a stator winding of an alternator with an internal high resistance ground fault. The currents under the fault condition are as shown in the figure. The winding is protected using a differential current scheme with current transformers of ratio $$400/5$$ $$A$$ as shown. The current through the operating coil is

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

For the system $$\frac2{\left(s+1\right)}$$, the approximate time taken for a step response to reach 98% of its final value is