Resource Management in a Distribution System with High-Penetration of Renewable Energies Considering Flexibility Concept

Abstract

Power distribution systems are experiencing restructuring owning to the increasing trend of integrating renewable energy sources as well as privatization in the network. In this regard, the dependence of power generation by renewable energy sources on meteorological characteristics would challenge the conventional procedures of operating the system. Respectively, while the expansion of renewable energy sources would facilitate supplying the demand loads locally; the issues associated with the uncertainty and variability of power generation by these units should be addressed in future operational schemes of distribution systems. This condition has resulted in the development of the flexibility concept, which shows the capability of the system to activate flexibility service from its resources to address potential operational issues. Based on these discussions, in this dissertation, various mathematical models are developed to facilitate the contribution of the local flexible resources in a distribution system in its operational management. Accordingly, several operational conditions (e.g. real-time energy imbalance, congestion issues, and intense ramping issues) are considered in this dissertation to study the benefits of local flexible resources in improving the reliability and flexibility of distribution systems with high penetration of renewable energy sources. Taking into account the rapid changes in the operation of distribution systems, the proposed models investigate different scenarios and optimization techniques to incentivize the contribution of local responsible resources in the operation of the distribution system. In this regard, the transactive energy concept is applied in this research work to develop value signals for motivating the re-scheduling of local flexible resources based on the operational issues in the network. It is noteworthy that in the first stage, a bi-level optimization model based on the Stackelberg game is deployed to develop a scheme, which enables the distribution system operator to exploit the operational scheduling of local flexible resources. Furthermore, with regards to the privatization of distribution systems, an operational structure is developed to facilitate the decentralized operation of multi-microgrid distribution systems while enabling activating flexibility service from local responsive resources. In this framework, the alternating direction method of multipliers (ADMM) is combined with the transactive energy concept to facilitate the decentralized operation of the grid. This algorithm would also enable separating the optimization of microgrids from the operation of the distribution grid. As a result, the developed scheme could be applied in future distribution systems with decentralized structures to operate the system in a flexible manner, while addressing the security concerns of independently operated local resources.