Reactive Power Control
Transmission connected generators are generally required to support reactive power flow. For example on the Great Britain transmission system generators are required by the Grid Code Requirements to supply their rated power between the limits of 0.85 power factor lagging and 0.90 power factor leading at the designated terminals. The system operator will perform switching actions to maintain a secure and economical voltage profile while maintaining a reactive power balance equation:
Generator_MVARs + System_gain + Shunt_capacitors = MVAR_Demand + Reactive_losses + Shunt_reactors
The ‘System gain’ is an important source of reactive power in the above power balance equation, which is generated by the capacitive nature of the transmission network itself. By making decisive switching actions in the early morning before the demand increases, the system gain can be maximized early on, helping to secure the system for the whole day.
To balance the equation some pre-fault reactive generator use will be required. Other sources of reactive power that will also be used include shunt capacitors, shunt reactors, Static VAR Compensators and voltage control circuits.
Read more about this topic: AC Power
Famous quotes containing the words power and/or control:
“Caring for children is a dance between setting appropriate limits as caretakers and avoiding unnecessary power struggles that result in unhappiness.”
—Charlotte Davis Kasl (20th century)
“We long for our father. We wear his clothes, and actually try to fill his shoes. . . . We hang on to him, begging him to teach us how to do whatever is masculine, to throw balls or be in the woods or go see where he works. . . . We want our fathers to protect us from coming too completely under the control of our mothers. . . . We want to be seen with Dad, hanging out with men and doing men things.”
—Frank Pittman (20th century)