DC bias suppression strategy for dual active bridge DC-DC Converter based on generalized second-order differentiation

In this paper, a generalized second order differentiator is constructed for the first time to solve the DC bias problem of DAB. Compared to traditional differential functions, the generalized second-order differentiator retains the differential effect of phase advance compensation for a specific frequency range, and eliminates the inherent high-frequency noise amplification problem of differentiation through a constructor. At the same time, it can freely adjust the amplitude characteristics of the phase advance compensation frequency range. This method is based on the traditional PI closed-loop control, By incorporating a parallel compensation control loop based on a generalized second-order differentiator, the DC bias of the inductance current is suppressed and the output ripple is reduced. Finally, the effectiveness of the control method was verified through MATLAB/Simulink simulation