Desenvolvimento de carregador rápido para veículos elétricos

Abstract

The increase in the combustion of fossil fuels to meet the growing demand for energy is one of the main causes for the increase in the concentration of carbon dioxide (CO2) in the atmosphere. In an attempt to slow this growing environmental pollution, the vast majority of the world’s nations have committed to reduce emissions of CO2 and other greenhouse gases. With this in mind, the transition from combustion vehicles to electric vehicles (EVs) is seen by many authors as one of the most promising developments for reducing greenhouse gas emissions and improving air quality. However, the biggest obstacle to the popularization of this type of vehicle is the time needed to recharge its batteries, during a trip for example. Having said all these paradigms, this dissertation presents the development of a three-phase fast charger for electric vehicle batteries. Nominally this charger is designed to deliver up to 50 [kW] and 100 [A] nominal to the battery. The first charging stage consists of an AC/DC converter coupled to an LCL filter and connected to the power grid at 220 [V] Phase-Phase. The second stage consists of a DC/DC interleaved converter, which is connected to the DC bus at 500 [V]. The charger is coupled to the battery in order to validate charging through the CC-CV method (Constant Current - Constant Voltage). The operation of the converter and its control technique are validated through simulations in the Matlab software, using the Simulink tool. Then, the charger is built using the AC/DC first stage and its operation is demonstrated using a bank of batteries. The control strategy is implemented in the DSP TMS320F28379D from Texas Instruments, using the software Code Composer. Satisfactory results were obtained in the battery charging control although the practical implementation is done on a small scale, the control system can be easily used at higher powers, just with adjustments in the control gains. The importance of compensating the dead-times that appear in the practical part is highlighted.