Technical valuation of generating units for participating in primary frequency control

Abstract

Technical specifications of the generating units affect their primary frequency reserve activation amounts (capacity) and quality (speed and maintaining), which have significant effects on power system security and reliability. This paper discusses the technical value of generating units, participating in primary frequency control, based on all their influential parameters. Initially, the formulation of the active power calculation of the generating units, in response to frequency variations, is developed. The concept of Weighted Average of Frequency Active Power Change (WAFAPC) is introduced, and its continuous and discrete formulation with different types of weighting function are proposed afterwards. Also, a novel general frequency profile is formulated for the incidents. Then the procedure for the technical valuation index calculation is presented while discussing its theoretical convergence issue and stopping criterion. The calculated index has the quantity with the same dimension and unit of electrical power which leads to a quantitative and meaningful comparison of the generating units with possible applications in many areas, such as remuneration, rescheduling, market designing, and technical-economic investigation. Numerical results, based on a real large-scale power grid validated data are presented. These include active power formulation validation, normal condition and incidents frequency variations statistical data, convergence demonstration, time-frame selection, and index calculation for various generating units types. The results demonstrate the accuracy and sufficiency of the proposed concepts and formulations.