Single-Phase Single-Stage PFC Based on a Novel Floating Capacitor Filter for Electric Vehicle Battery Charger Application

Global climate change has been influenced by natural variations in the Earths orbit and, more recently, by human-generated greenhouse gas emissions, leading to worrying consequences. CO2 emissions have increased considerably since 1990, specially in sectors such as electricity generation, industry and transportation. In this scenario, changes are necessary and the uptake of Electric Vehicle (EV) has been remarkable. In 2022, more than 20 million units were on the road, and a significant increase is expected by 2030. This poses important challenges, such as the need to improve the mileage autonomy and charging infrastructure of EV, highlighting the importance of power electronics research in this field. The aim of this doctoral thesis is to propose a new topology applicable to single-phase AC-DC converters for EV charging applications. The State of the Art (SoA) solutions mostly comprise Dual-Stage (2-S) solutions, with an intermediate DC bus formed by electrolytic capacitors. Single-Stage (1-S) converters skip the intermediate DC bus and exhibit more complex control strategies but offer advantages in power density, due to the absence of largest passive components needed in 2-S solutions. However, they transfer Low Frequency (LF) ripple from the Power Factor Corrector (PFC) to the output, which results in solutions not accepted by the industry. As a solution, a capacitor or an active filter can be connected to the output bus. It has been considered interesting to open a new line of research in the field of single-phase 1-S AC-DC converters that dispense with the large electrolytic capacitors. Thus, a new topology is proposed, which has been called as Floating Capacitor Integrated-Dual Active Bridge (FCI-DAB). It is a 1-S circuit with an active filter in the primary-side, connected to the High Frequency (HF) link. After the identification of the control variables, several modulation strategies for the FCI-DAB are presented, including electrical waveforms obtained from simulations. The FCI-DAB circuit is then ...