An energy cooperative system concept of DC grid distribution and PV system for supplying multiple regional AC smart grid connected houses

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This paper proposed a suitable control strategy for power sharing management for hybrid AC/DC residential PV systems. This control method is used as an Energy Cooperative Approach (ECA) to manage the power flow between a PV and battery-fed smart grid within a DC micro-grid, supplying some connected houses. In fact, using an ECA which is based on photovoltaic (PV) power transfer between three houses, connected to the AC network; through a DC micro-grid, the photovoltaic energy can be effectively used to satisfy the load demand. Such a process ensures a continuous demand satisfaction, lengthens the storage system life time by minimizing the resort of the battery, and alleviates the stress of the main grid minimizing the consumption of electricity fed by the AC grid. In fact, this strategy increases the system efficiency and the power supply quality. To achieve such purposes, a control algorithm for distributed flexible network residential PV systems was properly developed. The decision criterion for the developed supervisor is based on the instantaneous PV power, the required power, and the battery state of charge in order to manage the power flow under six operating modes. The control strategy was proposed also to regulate DC bus voltage and maintain the power balance within the micro-grid. The simulation results validated the effectiveness and feasibility of the proposed control strategy under various conditions. To highlight this strategy benefits, a comparative study between strategies without and with ECA was performed. The results of this study showed that using the ECA on a typical day, the energy PV contribution to satisfy the loads (Fpv) grows by a rate that varies from 15.5% to 23.45%, the battery contribution part (Fbat) recorded a decrease that varied between 8.77% and 18.42%, while the main grid contribution (Fgrid) was reduced by a rate that varied between 2.41% and 13.1%.