In this letter, a new methodology is proposed to extend the applicability of conventional power flow methods to islanded microgrids (MGs), operating with the droop control method. A slack bus is considered to be connected at a random MG node. The operational conditions of this slack bus as well as of the rest MG nodes are determined through an iterative procedure. The objective of this procedure is to force the active and reactive power flowing through the slack bus to zero, representing the islanded MG operation. The proposed approach has a similar accuracy with time-domain simulations, while it reduces significantly the required computational burden.

In this paper, a centralized control strategy for low-voltage networks is proposed, aiming to coordinate the droop characteristics of the distributed renewable energy sources. The main objectives are the overvoltage mitigation and the optimal network operation in terms of maximum power injection and uniform power curtailment. The distinct features of the proposed method are the incorporation of droop-based control techniques into the conventional optimal power flow formulation and the use of the sensitivity theory as a means to significantly decrease the computational burden. The validity of the developed method is justified using a genetic algorithm, while extensive comparisons with conventional centralized and decentralized control strategies indicate its superior performance in the operation of low-voltage networks.

This paper proposes a precise power flow algorithm for islanded hybrid AC/DC microgrids (HMGs). In our analysis, we have considered a multi-grounded unbalanced bipolar DC microgrid and a multi-grounded four-wire AC microgrid connected through one or more interlinking converters (ICs). The proposed method is based on the implicit ZBUS method, presenting fast convergence and robustness regardless of the R/X ratio of the lines. It can be applied in all network configurations including highly meshed distribution systems. Numerical simulations are conducted in a 12-Bus and a 47-Bus islanded unbalanced HMG to verify the validity of the proposed power flow approach considering several distributed generator (DG) operational modes.

During the last two decades, the use of residential photovoltaic (PV) systems has been widely promoted by governments through various support mechanisms such as feed‐in‐tariffs, net‐metering, net‐billing, etc. These support schemes have developed a secure investment environment, increasing the penetration level of PVs in low‐voltage distribution grids. Nonetheless, increased PV integration may introduce several technical problems regarding the secure operation of distribution grids. Battery energy storage (BES) systems can mitigate such challenges, but the high capital cost is one of the most important limiting factors towards the widespread use of these systems. In fact, the financial viability of integrated PV and BES systems under different support schemes remains an open issue. In this study, the profitability of PV and BES systems is evaluated through an advanced techno‐economic model, that provides the optimal size of PV‐BES system in terms of net present value, based on the electricity production and consumption profile of the installation, PV and BES systems costs, and electricity charges. The proposed model may be a useful tool for prosumers, grid operators and policymakers, to assess the impact of various incentive policy schemes and different BES operation strategies on the economic viability of PV‐BES systems.