Electric Vehicle Charging Systems: From Converter Level Optimization To Impact Analysis on Power Systems

The burgeoning adoption of electric vehicles (EVs) necessitates a comprehensive exploration of the charging infrastructure, delving into both the optimization of EV charger converters and the pivotal role of EV chargers in the power grid. This dissertation comprises six technical chapters, with a focused exploration of converters in Chapters 2 to 4 and an in-depth analysis of the role of EVs in power grids in Chapters 5 to 7.Chapters 2 to 4 showcase advancements in EV charger converters. Chapter 2 introduces a novel active harmonic reduction technique, mitigating the dominant third-order harmonic in the power factor corrector circuit’s input current. This innovation not only enhances grid power quality but also marks a critical step toward efficient and sustainable EV charging. In Chapter 3, a new gate signal modulation method in the dc-dc dual active converter minimizes conduction and switching losses, optimizing the charging process. Chapter 4 extends the converter optimization paradigm with a DC link voltage optimization method, enhancing the efficiency of the entire EV charger across ac-dc and dc-dc stages over the battery charging cycle. Chapters 5 to 7 transition seamlessly to the role of EV charging systems in the power grid. Chapter 5 explores the optimal utilization of bidirectional EVs for grid frequency support during critical events such as loss of generation and frequency drops. This chapter highlights the potential for EVs not merely as energy consumers but as dynamic contributors to grid stability. Chapter 6 presents a dynamic EV charging pricing strategy to distribute the EVs between charging stations (CSs) uniformly and thereby increase the revenue of the charging station operator (CSO) and enhance the charging satisfaction of EV users. Finally, in Chapter 7, a two-stage stochastic programming approach is developed for electric energy procurement in EV charging stations equipped with battery energy storage and photovoltaic generation. This innovative approach provides a roadmap for sustainable energy procurement, emphasizing the synergy between EV charging stations and renewable energy sources. In conclusion, this dissertation provides a holistic and pioneering exploration of EV charging systems, from converter optimization to grid integration. The research contributes significantly to the advancement of EV charging technology, offering solutions to enhance efficiency, power quality, and grid stability. The findings not only address current challenges in electric mobility but also lay a foundation for a sustainable and resilient energy future.