Predictive Control in LV Networks: A 3-Stage Approach for Smart Sustainable Buildings

Through its environmental targets and policies, the E.U. is pushing for the integration of residential distributed energy resources (DERs) and smart sustainable buildings (SSBs). Originally passive low voltage (LV) networks will face fundamental challenges in trying to cope with said strategy. Achieving proper controllability is not easy; DER forecasting uncertainty is high, and distribution system operators (DSOs) rarely own flexible devices. The low carbon footprint of SSBs should also not be sacrificed in the pursuit of mitigating technical issues. We propose a 3-stage, LV network constraints management approach, based on model predictive control (MPC). In Stage 1, the DSO transmits MPC-driven optimal set-points to each SSB by solving a multi-phase, multi-period AC optimal power flow (AC-OPF). In Stage 2, each SSB performs its own MPC-driven optimization (quadratic programming), trying to maximize its compliance without increasing its environmental impact (net consumption). In Stage 3, the missing service (non-compliance cases) is automatically re-assigned among compliant SSBs, without DSO involvement. The approach is validated on a 3-phase (3Φ), 4-wire LV feeder, with high penetrations of DERs and SSBs. A comprehensive performance analysis is performed, regarding costs, horizon choice and alternative solution approaches.