Switched Modeling of Three Phrase Voltage Source Converters as Rectifiers

Opene Israel Chukwuyem

2019-2023

Bachelor in Electrical Engineering and its Automation

ABSTRACT

In the domain of power electronics, Voltage Source Converters (VSCs) represent an essential component, offering a multitude of applications. This paper delves into an in-depth investigation on modeling of three-phase Voltage Source Converters (VSCs) in their rectifier mode, utilizing switched modeling techniques. This thesis aims to develop a comprehensive, coherent, and adaptable model for three-phase VSCs functioning as rectifiers. In contrast to existing methods that primarily employ averaged modeling, this study adopts a switched modeling approach, thereby capturing the intricate, time-dependent behaviors and nonlinear characteristics inherent in the system. With the global push towards renewable energy sources and their integration into power systems, the relevance and need for such modeling have become more crucial. The research initiates with an overview of the fundamental concepts related to three-phase VSCs, followed by an in-depth exploration of its operation in rectifier mode. The process of model development encapsulates the dynamic behaviors of the converter, emphasizing the necessity of switched modeling. The converter system's complexities are dissected, including its switching states, the inherent distortion in the output waveform due to harmonic frequencies, and other pertinent factors that may affect its performance. The study concludes with a further expounding of the model's potential implications in the field of power electronics and renewable energy. Additionally, it suggests potential avenues for further research, specifically focusing on advancing the proposed model to handle more complex converter configurations and load conditions. In essence, this thesis provides an insightful contribution to the knowledge base of three-phase VSCs as rectifiers using the switched modeling technique by offering a more accurate, versatile, and in-depth model that captures the dynamic, nonlinear characteristics of the system, serving as a reliable foundation for future work in this area.

Keywords: Three-phase VSCs, rectifiers, switched modeling, pulse-width modulation, IGBTs