A Local Capacity Market Providing Local and System-Wide Flexibility Services

Hosna Khajeh,Miadreza Shafie-Khah,Hannu Laaksonen,Mohammad Reza Hesamzadeh,Hooman Firoozi

doi:10.1109/access.2021.3069949

Abstract

A large amount of renewable energy sources and electric vehicles will be integrated into future electricity distribution and transmission systems. New flexibility services from distribution network are needed to manage the related challenges. This paper proposes a local flexible capacity market (LFCM) in the distribution network providing system-wide and local flexibility services for transmission (TSO) and distribution system operators (DSO). The TSO and the DSO play the role of buyers, whereas prosumers connected to the distribution network are the sellers. The LFCM consists of three stages. At the first stage, the offers of flexibility sellers are matched with the bids of flexibility buyers aiming to maximize the social welfare of all participants. At the second stage, the accepted flexible capacities are checked by the DSO not to violate the constraints of the local network. The third stage accepts the offers of the sellers based on the results of the previous stage. The results related to the chosen case study demonstrate that the local flexible resources can help the DSO control the voltage and manage periods of congestion. Besides, the owners of the resources can obtain revenues by selling flexibility services while improving electricity supply reliability.

Highlights

CONTRIBUTION This paper proposes a three-stage local flexible capacity market (LFCM) capable of providing flexibility services for distribution system operators (DSO) and transmission system operators (TSO) needs
The local network needed only upward flexibility and did not require any downward flexible capacities. These amounts of flexibility will be offered to the LFCM by the DSO
The DSO bids for its required upward flexibility to the LFCM operator, having solved the optimization problem (1)-(16)

Summary

Introduction

Contemporary power systems need to deal with the increasing penetration of intermittent renewable energy sources (RES) and electric vehicles (EV) in distribution networks. The system operators, including both the transmission system operators (TSO) and the distribution system operators (DSO), need to resolve these issues by utilizing more flexibility services in their networks [2]. Flexibility services are typically categorized into systemwide and local services based on the type of system operator (TSO or DSO) utilizing the services [3]. System-wide flexibility services are procured by the TSOs. Regarding European terminology for system-wide services, these services mainly consist of different types of reserves such as frequency containment reserves (FCR), fast frequency reserves (FFR), and frequency restoration reserves (FRR) [5]

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Conclusion