The Relationship of Primary, Secondary, and Tertiary Regulation / Dispatch under High Wind Penetration

This paper investigates the operational benefits of three different methods of providing secondary reserves in National Grid system under future higher penetration of wind generation. New automatic balancing mechanisms that will be feasible under National Grid’s new Electricity Balancing System (EBS) were of particular interest to the system operators. Secondary reserve products including manual balancing operations, automatic balancing orders, and Automatic Generation Control (AGC) were evaluated using DNV GL’s operational analysis simulation tools SFLEX and KERMIT as well as a new market cost model developed by National Grid. A vigorous dynamic simulation of entire power system is performed that includes inertial, governor and regulation response as well as AGC. High resolution load and wind profiles are simulated and incorporated into the model to capture the system variably in the future. The impact of relative timing and delays in various control schemes as well as their interrelationships on system frequency control have been examined. Our findings show that the new EBS reduces the urgency to implement a new secondary reserve product as manual operators using the new automation facilities of EBS are able to sufficiently control system frequency to within the limits of current National Grid standards.