## 4 Conclusions  
Voltage control of LV networks is a big concern for DSOs, especially in networks with high integration levels of DG. In this paper, a new algorithm for voltage control in LV grids that takes advantage of the available DER and flexibility from domestic consumers is presented. The proposed approach operates in two different time frames: a preventive plan for \(n\)-hours ahead and a scheme to implement corrective measures in real-time. Simulation results, in preparation for a trial in a real environment, were obtained where it was shown that the proposed approach was able to solve all of the foreseen voltage violations, recurring to the available flexibility from the different existing DER. The unbalanced three-phase power flow algorithm used by the LVC tool was first evaluated by comparing the voltage values obtained with actual historical values for four typical days, representative of the four seasons. The algorithm showed a good performance, presenting MAPEs of 0.26% and 0.27% for the Summer and Autumn days, respectively, the latest data available. The LVC algorithm was tested using a real LV network, with real consumption and generation data. In the simulation scenario, it was shown that the LVC algorithm was able to regularize all of the foreseen voltage constraints during the peak solar production period of the day, recurring to the flexibility provided by the DSO-owned storage device and the flexibility provided by the domestic consumers. Furthermore, it was also shown that the LVC tool has a positive impact on the active power losses, although this is not a direct objective of the algorithm. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Simulation Day**} & \multicolumn{3}{c}{**Annual Estimation**} \\ \cline{2-7}  & **Pre-LVC**, & **Post-LVC**, & **Reduction,** & **Pre-LVC** & **Post-LVC**, & **Reduction,** \\  & **[kWh]** & **[kWh]** & **[\%]** & **[kWh]** & **[kWh]** & **[\%]** \\ \hline Phase R & 5.90 & 5.77 & 2.21\% & 3182.15 & 3137.55 & 1.40\% \\ Phase S & 7.56 & 7.15 & 5.41\% & 3354.74 & 3196.12 & 4.73\% \\ Phase T & 3.72 & 3.70 & 0.57\% & 1833.82 & 1816.17 & 0.96\% \\ Phase N & 3.64 & 3.48 & 4.60\% & 1830.03 & 1801.79 & 1.54\% \\ \hline Total & 20.82 & 20.10 & 3.50\% & 10200.74 & 9951.63 & 2.44\% \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Power losses, with and without the application of the LVC tool. Figure 24: Control action. Generator connected to node 27 (2). With the growing integration of DG and electrification of several sectors--such as transportation--, it is envisioned that LV networks will become highly stressed in the near future. The proposed algorithm intends to be a tool to apply in stressed LV networks, increasing the efficiency and security of operation, at the same time encouraging the participation of the private customer in grid operation. From the operator point-of-view, this kind of tools have the potential to defer large investments in grid reinforcement, while maintaining the quality of energy supply. Within the framework of the H2020 InteGrid project, the algorithm will now be tested in a set of smart grid demonstration networks operated by EDP Distribuicao, located in Portugal, in the first quarter of 2020 in the exact same network that was used for the simulation studies presented here. [PERSON] carried out the main research task and wrote the manuscript. [PERSON] proposed the original idea and contributed to the revision of the obtained results and of the whole manuscript. All authors have read and agreed to the published version of the manuscript. The research leading to these results has received funding from the European Union's Horizon 2020--The EU Framework Programme for Research and Innovation 2014-2020, under grant agreement No. 731218. The sole responsibility for the content published in this paper lies with the authors. It does not necessarily reflect the opinion of the European Commission. The European Commission is not responsible for any use that may be made of the information contained herein.