What is Balancing Authority A's ACE reading?
Final answer: The ACE for Balancing Authority A is +32 MW. This is calculated taking into account the system's imbalance of 40 MW and adjusting for the frequency bias using the interconnection frequency.
Explanation:
The Area Control Error (ACE) is a measurement used by a Balancing Authority (BA) to help maintain the balance between electrical generation and load.
The BA maintains this balance by controlling the Interconnection frequency. In this case, Authority A has a scheduled import of 300 MW but is actually importing 260 MW, that is a discrepancy of 300 - 260 = 40 MW.
Then, we calculate the frequency discrepancy by subtracting the nominal frequency (60 Hz) by the actual frequency (59.94 Hz), resulting in 60 - 59.94 = 0.06 Hz.
So, the total ACE is the system imbalance added to the frequency bias adjustment, calculated with (-40 MW) - (-120 MW/0.1 Hz * 0.06 Hz), which calculates to -40 MW - (-72 MW) = +32 MW, which is a positive value. So, the correct answer is B. +32MW.