An AC OPF based Clearing Mechanism for Local Flexibility Markets

Local flexibility markets have emerged as a promising solution to solve distribution grid's constraints at a lower cost than grid reinforcement. In this paper, we propose a local flexibility market framework based on optimal power flow (OPF) computation to allow a Community Distributed System Operator (C-DSO) to coordinate local flexibility provided by distributed generators and residential consumers. This local flexibility market allows the Distributed System Operator (DSO) to select the most cost-effective mix of flexible assets that addresses voltage excursions and grid congestions. It builds on an existing OPF formulation applicable only to energy markets, and extends it to the coordination of electrical flexibility. It considers active and reactive power while being suitable for imbalanced distribution grids analysis. Finally, it is implemented on the European low voltage test network with real consumption data and large solar PV penetration to solve local grid constraints. The formulation optimises the flexibility effort while the power flow accuracy presents an error below 2.9% as compared with OpenDSS.