DPWM Delay Influence in the High-Frequency Beating Modelling of dc Microgrids

Abstract

This paper undertakes a comprehensive analysis investigating the influence of the DPWM delay on the high-frequency modeling of dc microgrid connected converters. When multiple converters are connected at the same dc bus, the switching frequency of one converter can be seen as the perturbation frequency of another, resulting in the so-called beating phenomenon. A high-frequency circuit model is indispensable to comprehend this effect. This model not only plays a pivotal role in the stability analysis of interconnected converters but also demonstrates that the DPWM delay is a crucial element of an accurate circuit model. The case scenario is a dc microgrid composed of two buck converters in a cascaded connection. While this study focuses on this specific dc microgrid, the proposed methodology can be applied to different topologies, offering improved stability in a wide range of applications. The theoretical analysis is further validated by simulation results.