What is the impact on frequency and ACE during a loss of internal load?

When internal load is lost in a power grid, it results in a decrease in the total demand for electricity. This change has a direct impact on both frequency and the Area Control Error (ACE) of the grid.

In the context of power systems, frequency is directly related to the balance between generation and load. When there is a loss of internal load, the generation of electricity exceeds the reduced demand. This surplus of generation causes the system frequency to rise above its nominal value, which reflects that there is more supply than demand.

ACE is a measure used to determine the balance between generation and load within a specific area. It accounts for the difference between scheduled and actual power flows, as well as frequency deviations. Given that the loss of load results in an oversupply of power, the ACE may not see immediate changes, particularly if the generation is not adjusted accordingly. Therefore, the ACE remains consistent in this scenario, as the system stabilizes after the initial impact of the loss of load.

Thus, the correct answer highlights that during a loss of internal load, you would see an increase in frequency alongside a stable ACE.