Applying a Generation Unit Commitment Problem in Integrated Power System Development Tasks

Abstract

One of the key stages in Ukraine’s integration into the European Union is the accession of NPC “Ukrenergo”, currently certified as the transmission system operator of Ukraine, to full membership in the European Network of Transmission System Operators for Electricity (ENTSO-E) as of January 1, 2024. The next stages of Ukraine’s integration into the EU involve the adoption and transposition of European legislation into Ukrainian law, which should ensure harmonization not only of political practices but also of a unified, ideally identical, methodological framework across the EU for analyzing and solving various practical problems and tasks. This includes the development of Ukraine’s national power system, which must methodologically align with the existing ENTSO-E methodological documents. According to the current ENTSO-E Cost Benefit Analysis (CBA) methodology, the development of interconnected power systems (IPS), both national and cross-border, is addressed through three distinct tasks implemented as mathematical models. First stage: Mathematical modeling of the development of generation for the IPS as a whole or for a limited number of nodes — known as market simulation. Second stage: Based on the results of market simulation, modeling of the transmission and, if necessary, distribution network or its individual elements is carried out — grid simulation. The grid simulation produces a list of candidate projects for network modification, which may include both the addition and removal of certain network elements. The selection of candidate projects for practical implementation is based on an integrated numerical assessment that considers the impact of each project on nearly all important socio-economic, environmental, ecological, technical, and other aspects. Therefore, the solution obtained from market simulation determines the possible future directions for the development of the national power system, making it essential to obtain an optimal solution already at this initial stage. One of the tools for obtaining such an optimal solution is the use of a mathematical model for optimizing the composition and operating modes of generation sources — Unit Commitment Problem (UCP). As an example, the article presents the results of applying the UCP model to two alternative scenarios for the technological development of nuclear generation capacities: using power units with an installed capacity of 1000 MW or more operating in a stable generation mode and using small modular reactor units operating in a daily load-following mode.