Dynamic Operation of AC Micro-Grid Integrated PV-BESS using 3-phase97-level CHBMLI

The modern power system advances to an inverter dominant system, due to the high penetration of Renewable Energy Source (RES) based Distributed Generation (DG). The effective operation of the AC micro-grid can be achieved by employing an efficient Cascaded $H -$bridge Multilevel Inverter (CHBMLI) integrated with RES across the Point of Common Coupling (PCC). In this paper, the grid-connected 3-phase, 7-level CHBMLI topology with Photo Voltaic-Battery Energy Storage System (PV-BESS) is presented. The bidirectional DC-DC Battery system is connected to solar PV for maintain the constant DC input voltage across CHBMLI bridges irrespective of irradiation ‘G' $(W/m^{2})$. To increase the utilization and the reliability of PV-Battery power effectively at the load end, it is integrated with the AC grid. In this proposed work, the performance analysis of voltage-current controller for the bidirectional and DQ-control technique under dynamic conditions of solar-PV, DG-MLI power, and load demand are examined. The advantage of the proposed PV-battery CHBMLI control is that whole capacity of the PV-battery system is utilized by enhancing reactive power support along with active power when solar insolation is low. The mathematical modelling of the system is presented and design of 3-kVA system is carried out. The simulations in MATLAB/ Simulink environment verified the design of the controller and effectiveness of the proposed system under dynamic conditions.