Optimal Steady-State Operation of an Isolated Small Active Distribution Network

Managing small and islanded distribution systems is becoming more challenging due to integrating different distributed energy resources to supply the load demand. This paper presents a co-simulation-based optimisation framework for the optimal steady-state operation of distributed energy resource assets integrated into a small islanded active distribution network. To this purpose, an asynchronous framework based on DIgSILENT<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> PowerFactory<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TM</sup> and Python for modelling and optimisation, respectively, is employed. In particular, the key innovation consists in the implementation of quasi-dynamic simulations, enabling the accurate representation of network operational conditions over mid and long-term time horizons. The proposed approach is able to optimise the daily dispatch of Battery Energy Storage Systems, biofuel generators, and photovoltaics, minimising biofuel consumption while ensuring voltage stability. The approach is tested on CIGRE Task Force C6.04 distribution network, properly modified to emulate islanded grid. Simulation results demonstrate the practical relevance and potential for real-world application, and highlight significant improvements in resource management, contributing to enhanced sustainability and resilience in small active distribution networks.