Abstract:
To improve the dynamic performance and anti-jamming capability of the energy storage unit in DC micro-grid, a seamless switching control strategy for bidirectional DC/DC converter with energy storage is presented in this paper. According to the change of DC bus voltage, the adaptive switching between charging and discharging of energy storage unit can be realized to keep the bus voltage stable. On this basis, taking into account the nonlinear characteristics of the bidirectional DC/DC converter, a nonlinear seamless current inner loop is introduced into the controller. The nonlinear fal function is used to adjust the error feedback coefficient online, which improves the dynamic performance and the robustness of the control strategy. As a result, the charging/discharging seamless switching of the energy storage bidirectional DC/DC converter is realized. The feasibility and validity of the proposed strategy are verified by simulation and experiment. Seamless switching of charging and discharging of energy storage unit can be achieved under bus voltage drop, steep rise and system parameter change conditions.