A transmission path rated at 550 MVA has 500 MW and 55 MVAR of power. What action should the system operator take?

The correct choice indicates that no immediate action beyond continued monitoring of the situation is required for the transmission path rated at 550 MVA, which is currently carrying 500 MW of real power and 55 MVAR of reactive power.

To understand this, it’s important to consider the relationship between active (real) power, reactive power, and the apparent power rating of the transmission path. The apparent power (S) can be calculated using the formula:

[ S = \sqrt{P^2 + Q^2} ]

Where:

• ( P ) is the real power (500 MW in this case),

• ( Q ) is the reactive power (55 MVAR).

Plugging in the values:

[ S = \sqrt{(500)^2 + (55)^2} ]

[ S = \sqrt{250000 + 3025} ]

[ S = \sqrt{253025} ]

[ S \approx 503.01 \text{ MVA} ]

The calculated apparent power (approximately 503.01 MVA) is well within the rated capacity of the transmission path (550 MVA). Since the line is not exceeding its capacity, there is no immediate need to reduce power