The generation of power in a power plant has to be controlled to

SOLUTION

• The generation of power in a power plant has to be controlled to meet the demand of load and frequency both because the frequency of the electric system depends on the active power balance.
• If a generation-load active power imbalance occurs, the frequency will either increase or decrease, thus moving away from its nominal operating value.
• To control the frequency, the active power balance must be restored.
• If the total generation power is more than the total load power, the system frequency will rise
• If the total generation power is less than the total load power, the system frequency will fall.
• Frequency control is irresponsible for stable operation.

NOTE:

The system performance in terms of how the change in power affects the charge in frequency is evaluated through the Area frequency Response characteristic (AFRC).

• It’s unit in p.u. is MW/Hz.
• It has given the combined effects of the frequency characteristic of the load of the area and the inherent governing system of the area.