Design of 50kW Multilevel AC/DC Converter Fed Two Phase Parallel Interleaved DC-DC Converter for Fast EV Charging Stations

Abstract

Each car manufacturer already has electric vehicles (EVs) on their roadmap and considers them as part of a sustainable solution for reducing greenhouse gas emissions, as they will contribute to a greener transportation system. A key component of an EVs is its energy storage system (ESS). The development of a reliable infrastructure for charging electric vehicles is among its most crucial components. Electric vehicles (EVs) are charged with a single-phase bridge converter, which delivers a peaky current that reduces power profile that results in increased losses and charging time of EV battery is very high. A conventional single-phase diode bridge rectifier (DBR) with a power factor correction (PFC) circuit at the input of an LEV charger is responsible for high conduction losses. In this paper, a novel multilevel unity power factor (UPF) three phase AC-DC converter coupled with interleaved buck converter (IBC) based charger provide an efficient and fast charging solution for EVs. It minimizes switching losses and provides an enhanced step-down conversion ratio, which is suitable for EV charger where the input voltage is high, and the duty ratio is less than 50%. This article also aims to improve the PFC rectifier responsiveness and lessen the complexity of the control system. The need for an input filter is extensively studied in three-level PFC rectifier voltage waveforms.Complete system design is carried out for a 3-ϕ, 50 kW, EV charger, with 230 <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</inf> line to neutral, 50 Hz AC input and 200 ̶ 400V wide range DC output voltage for EV battery. The proposed converter is capacity to produce improved power quality by the decrease in total harmonic distortion (THD) of input current, PFC, detects almost no zero-crossing and precise output voltage regulation. The MATLAB/ SIMULINK results show the anticipated outcomes of the EV charger. In accordance with the international IEC-61000-3-2 PQ standard, this EV charger enhances the system's reliability and efficiency as well as its near UPF. It is a viable option for fast charging for EVs based on the results, which indicate a peak efficiency of 97.3% with 0.9997 PF and source current THD of 2.57%.