The LLC resonant converter is a widely used DC/DC converter that offers the benefit of enabling soft switching compared to classical DC/DC converters. However, traditional PI control strategy based on a linear model has drawbacks such as slow dynamic response and poor anti-interference performance. To overcome the shortage, a passivitybased control strategy based on the Euler–Lagrange (EL) model is proposed in this paper to improve the dynamic performance of the half-bridge LLC resonant converter. In addition, the stability of the system based on the proposed strategy is analyzed and verified. Further, the effectiveness and performance of the proposed strategy is verified in the simulation by comparing with the traditional PI controller. Finally, a prototype was built to verify the dynamic performance of the LLC resonant converter based on the proposed control strategy.

Dual active full-bridge (DAB) DC–DC converters are widely used in DC microgrids and various fields of power electronics. It has the advantages of high-power density, easy to implement soft switching and bi-directional power transfer capability. Conventional linear controllers have difficulty in meeting the increasing demands for speed and robustness. In this paper, a control strategy based on the Brayton–Moser theory of power shaping is proposed to improve the control strategy of DAB DC–DC converters. The DAB DC–DC converter is modelled and the controller is designed based on the Brayton–Moser power-shaping theory. A simulation of the DAB DC–DC converter is constructed and a comparative analysis is carried out for three control strategies of PI control, passive control and power-shaping Brayton–Moser control under different operating conditions.