Beat Frequency Oscillation Analysis for a DC Microgrid with Multiple Boost Converters

In general, energy sources and electronics loads are connected to DC microgrids via power electronic converters. However, interactions of these power converters may introduce instability issues into the system. One typical problem is the generation of the beat frequency oscillation caused by the minor differences of switching frequencies between power converters. This paper analyses the output terminal characteristics of the Boost converter, and a small signal model is built to analyse the beat frequency oscillation between two parallel-connected Boost converters. Based on the analysis, a hybrid method is proposed to alleviate the beat frequency oscillation. Simulation and experiments results are presented to show the effectiveness of the proposed solution.