A Multiport High Step-Up DC-DC Converter with a Bidirectional Port for Battery and Photovoltaic Panels Integration in Solar Power Plants

In solar power plants with energy storage systems (ESSs), a multi-port DC-DC converter (MPDC) equipped with a bidirectional port is more favorable than multiple single-input converters due to its simpler control, higher efficiency, lower cost, and higher power density. This paper proposes a multiport DC-DC converter equipped with a bidirectional port for solar power plants. The proposed converter combines a multi-input cascaded structure with a switched capacitor (SC) cell, a three-winding coupled inductor (3WCI), and a bidirectional port connecting the ESS to the system. Key advantages of this converter include low normalized pick inversed voltage (NPIV) on semiconductors, continuous input current with low ripple, high voltage gain, common ground, high efficiency, and the capability to operate effectively in different operating states. Such performance of the proposed MPDC under various operating states facilitates the implementation of diverse energy management strategies within the grid. The various operating states of the proposed MPDC are analyzed in steady state, and the validation of the mentioned advantages is supported by presenting comparative results with other DC-DC converters. Finally, the results obtained from the analysis of the proposed converter are validated through simulations performed utilizing a co-simulation link between MATLAB and PSCAD/EMTDC software.