Load following control issues in the Spanish power system

Load following is carried out in a centralized way in the current Spanish power system, with several AGC modules of the main generation companies responding to the requirements of a master regulator. This service is provided under competition as an ancillary service, including a dedicated daily market. This paper shows that the current structure of the Spanish AGC system can be potentially improved from the load following performance point of view by using new algorithms of load following control. Load following control is proposed to reduce frequency deviations during normal system operation, using, at the same time, the lowest amount of regulation energy as possible, and, consequently, enhancing system reliability and economy.