Question

3. Suppose a three-phase fault occurs at the bus two end of one of the lines supplying bus 2, on the line side of the breaker. Eventually, the fault will be

cleared by opening the breakers at both ends of the line. For now, consider the fault-on conditions. (a) Determine the fault phase currents at bus 2 for the original system without the additional 25% load. You may use the short circuit formula from lecture or Power World. (b) Determine the fault phase currents at bus 2 for the new system with the additional load and any reinforcements, such as the new line, new operating point (generator dispatch and/or terminal voltage), and new capacitors (if any). You may use the short circuit formula from lecture or PowerWorld. (c) Compare the original system fault currents to the new heavily loaded system fault cur- rents. What conclusions can you make?