Reciprocating Connection of Dual Active Bridge DC/DC Converter with PV Integration

Abstract

Due to the renewable energy integration in the electric power network, interest of utilities towards using medium voltage DC in the utility network is increasing gradually, so this paper proposes interconnection between the main AC grid and the PV power plant based on dual active bridge (DAB) DC/DC converters with reciprocating connection. The dual active full-bridge (DAB) has many advantages such as electrical isolation, high-ratio buck-boost, easy soft-switching control, and multiple modularization through series-parallel combination. This paper focuses input series output parallel (ISOP) dual active bridge (DAB) DC/DC converters, and the reciprocating connection can provide different medium voltage levels at the output, facilitating the connection of main grid and PV power plant. Considering the modular parallel operation of the DAB converter in high-power applications, the power balance problem of the parallel output DAB converter is discussed in a more detailed way. For the validation of the feasibility of model proposed in this paper, it is simulated and analyzed in Power System Computer Aided Design (PSCAD).