In this paper, an innovative method for managing a smart-community microgrid (SCM) with a centralized electrical storage system (CESS) is proposed. The method consists of day-ahead optimal power flow (DA-OPF) for day-ahead SCM managing and its subsequent evaluation, considering forecast uncertainties. The DA-OPF is based on a data forecast system that uses a deep learning (DL) long short-term memory (LSTM) network. The OPF problem is formulated as a mathematical mixed-integer nonlinear programming (MINLP) model. Following this, the developed DA-OPF strategy was evaluated under possible operations, using a Monte Carlo simulation (MCS). The MCS allowed us to obtain potential deviations of forecasted data during possible day-ahead operations and to evaluate the impact of the data forecast errors on the SCM, and that of unit limitation and the emergence of critical situations. Simulation results on a real existing rural conventional community endowed with a centralized community renewable generation (CCRG) and CESS, confirmed the effectiveness of the proposed operation method. The economic analysis showed significant benefits and an electricity price reduction for the considered community if compared to a conventional distribution system, as well as the easy applicability of the proposed method due to the CESS and the developed operating systems.Energies 2020, 13, 1764 2 of 21
Centralized and Decentralised Energy Storage SystemFor an SCM, there are two main common options to place storage units-a centralised energy storage system (CESS) and a decentralised energy storage system (DESS). Existing research deals with CESS and DESS, describing their useful properties, limitations, and applications.Generally, energy storage systems (ESSs) are used in microgrids to compensate the intermittent nature of RE, to improve the RE penetration level and to grow the self-consumption rate, reducing dependence on the grid [6]. The CESS represents a central ESS that is directly operated by the energy management system (EMS) of a microgrid. A DESS represents numerous small ESSs allocated in a microgrid. They can be operated by local users, by aggregators, or by the central EMS. The CESS increases the overall efficiency and the resiliency of the microgrid [7], whereas, on the other side, the DESS maximises the local impact of ESSs to adjust to local load profiles [8].According to the study presented in [9], the deployment of a DESS reduces the power losses in the distribution network and can support the load demand with a rapid response [10]. Nonetheless, the deployment of a DESS needs an appropriate mature infrastructure and a control mechanism, both of which are more expensive and complex than those required in the case of a CESS.According to [1], for the same operating conditions of the photovoltaics (PV) generation and ESS capacity, a CESS exhibits a better (of about 17%) reduction of the grid power use, compared to a DESS. In [11], the authors revealed that by using a CESS for the operation of a microgrid, lower operational costs c...
