What happens to frequency and ACE when there is a loss of internal generation?

When there is a loss of internal generation in a power system, the immediate consequence is an imbalance between generation and load. This imbalance typically leads to a decrease in system frequency. Frequency is a measure of how often the alternating current changes direction per second, and in a power system, a higher load without sufficient generation will cause the frequency to drop.

Alongside this frequency change, the Area Control Error (ACE) also reflects the performance of the system in maintaining balance between generation and load. ACE is influenced by both frequency and the power interchange with neighboring areas. When internal generation is lost, it creates a deficit that manifests as an increase in ACE, which indicates that the area is now producing less power than it requires to meet demand.

Thus, the accurate outcome of losing internal generation is a decrease in frequency, as the load exceeds available generation capacity, and an increase in ACE, signifying the deviation from the desired generation-load balance.