AC-link Fundamental Component Extraction in DAB DC/DC converter using SO-SOGI for Minimization of Back Power

The most popular converter for bi-directional DC power flow with inherent zero voltage switching (ZVS) operation and galvanic isolation is DAB DC/DC converter. The optimum efficiency of the DAB converter is achieved by operating both the H-bridges in ZVS condition. The range of ZVS operation is limited with SPS control and this limitation is overcome by DPS control. The DPS control increases the system efficiency as well as limits the back power flow into the system with appropriate combination of inner and outer phase shifts. In this paper, the range of ZVS operation is identified by using harmonic analysis. The AC-link fundamental component extraction using SO-SOGI has been proposed for minimization of back power flow into the system. To validate the proposed modified DPS controller for DAB DC/DC converter, a detailed simulation is carried out using MATLAB/Simulink with a 10kW and 10kHz system.