Decoupled Modulation Method for Four‐Port Converters Based on Switch‐Sharing Technology

ABSTRACT

The four‐port converter based on switch‐sharing technology has the advantages of high integration and small number of devices in the bipolar DC microgrid, but the coupling problem in its control system can easily lead to phase‐shift mutation, causing serious oscillation of current and voltage. Aiming at this problem, this article proposes a decoupling modulation method suitable for switch‐sharing model. Based on the traditional single‐phase‐shift (SPS) control, this method introduces a segmented phase‐shift strategy. By independently controlling the driving signal of the switch tube, the mutational phase shift is corrected, so that the disturbance in the current commutation stage is transferred to the power transmission stage. Compared with the existing control strategy, this modulation method can effectively suppress current oscillation and voltage fluctuation. Finally, the effectiveness of the algorithm is verified by experiments.