Peer-to-peer trading-based efficient flexibility securing mechanism to support distribution system stability

With the expected increase in the energy transaction of prosumers, there are increasing issues related to maintaining and improving the stability of a distribution system. The flexibility of a prosumer can be effectively used to improve the stability at much reduced cost. Most of the existing studies have separately approached energy and flexibility transactions causing inefficiency. This paper proposes a new peer-to-peer (P2P) transaction mechanism that enables both flexibility and energy transactions to be considered and balanced. In this mechanism, a P2P community has an obligation to reserve the flexibility during P2P energy transaction to ensure an intact distribution system. The prosumers can trade the flexibility among each other to avoid a penalty by securing the required amount of flexibility given by the distribution system operator. A dynamic flexibility index is proposed to quantify to represent the degree of flexibility that can be provided by a prosumer. A Stackelberg game approach using the dynamic flexibility index is modeled to solve the bidding process. The proposed mechanism is described and analyzed through a case study for prosumers with battery energy storage and photovoltaic systems. As a result of case studies, in the proposed mechanism, prosumers can maximize profits through the optimal use of energy resources and simultaneously maintain the stability of distribution systems.