In a simple power system with three lines, if one line trips while initially loaded at 200 MW, what will the loading on the remaining lines become?

When one line in a three-line power system trips while initially loaded at 200 MW, the remaining two lines must accommodate the total load previously carried by all three lines. Assuming that the initial system is balanced and that the load is distributed evenly across the lines, each line would initially carry approximately 66.67 MW (200 MW ÷ 3 lines).

When one line trips, it removes its 66.67 MW from the system, leaving the total load to be shared by the two remaining lines. Therefore, the remaining load of 200 MW will be split between the two lines, resulting in each line carrying 100 MW.

It is important to check the operational limits of both remaining lines, but in a standard situation, carrying 100 MW each typically does not violate transmission line capacity, assuming the original lines were capable of supporting at least their share of the load. Thus, option stating that the loading on the remaining lines would be 300 MW together (150 MW each) is not applicable because the capacity isn’t exceeded.

The correct answer aligns with the calculation and the assumption that after the line trips, the remaining lines effectively share the burden of the total load without exceeding their limits, resulting in 300 MW total loading