Bidirectional Droop Control of Hybrid Microgrid Interface Converter Based on Sliding Mode Control

Due to the different dynamic characteristics of AC-DC subnets in hybrid microgrids, power fluctuations will occur between subnets on both sides of the bidirectional interface converter (BIC) when the system's load changes, and the dynamic response of AC bus frequency and DC bus voltage will become poor. Therefore, a bidirectional droop control strategy based on fractional order sliding mode controller (FOSMC) is proposed. By introducing the sliding mode variable structure control with strong robustness, fast response speed and strong anti-interference ability into the BIC control, an improved fraction-order sliding mode controller is obtained, which can improve the transient response process of the system. The simulation model is built by Matlab/Simulink platform, and the effectiveness of the control strategy is verified under various working conditions. Compared with the traditional bidirectional droop control, the proposed control algorithm can not only guarantee the original steady-state characteristics of the system, but also accelerate the response speed of the whole system, suppress the instantaneous fluctuation of BIC transmission power in the transient process, reduce the reaction of power fluctuation on the AC and DC subnets bus, and improve the dynamic performance and anti-disturbance performance of the whole system.