Fuzzy Logic Based Direct Power Control of Dual Active Bridge Converter

This paper presents the fuzzy logic based direct power control (FLDPC) for dual active bridge (DAB) converter. The suggested scheme incorporates the advantages of fuzzy logic controller and direct power control (DPC), thereby enabling an enhanced control over power transfer of DAB converter. Consequently, the control provides an improved dc-link voltage regulation, better dynamic response with and accurate reference tracking. The control of output voltage depends on the power transfer whereas; the power transfer is controlled by the phase shift ratio across the primary and secondary bridge voltage waveform. With the voltage error signal and the integral of error as linguistic inputs to fuzzy controller, the power reference is generated. Thereafter, the phase shift corresponding to the given power reference is calculated, to control the power flow. The exact converter model is not required for the fuzzy based method. The single phase shift method (SPS) is used for DAB switching and the output voltage is thus controlled using power reference. The dynamic performance under step load change condition is improved as the controller provides a quick power handling and control. To verify the proposed control method, a 2kW DAB converter with FLDPC is verified by simulation in MATLAB-Simulink.