Linearized Modeling Methods of AC&x2013;DC Converters for an Accurate Frequency Response

Abstract

Wideband harmonics and resonances are challenging the stability and power quality of emerging power-electronic-based power systems, and therefore, harmonic modeling and analysis of power converters are becoming even more important. However, the complex interactions on both ac and dc sides of a converter and the propagated interaction to other systems have been a challenging task for modeling. This paper introduces a systematic overview of different linearized modeling methods. It is followed by a step-by-step elaboration of the underlying principles of different methods, and practical difficulties in modeling are discussed. A comparison of these methods is presented. Simulation results show that the harmonic state-space modeling method provides an efficient way to analyze both steady-state frequency coupling and dynamic harmonic interactions in power-electronic-based power systems.