Developing an Efficient Electric Vehicle Charging Framework

Electric Vehicles (EVs) are the latest technology in the automotive industry. EVs have been introduced to the automotive market to account for the worsening of environment and the increase in energy demand of transportation sector over the years. However, charging efficiency remained the concern for EV owners or potential EV buyers. An efficient EV charging includes reduced charge time, effective use of energy and electricity source, and a good battery thermal management system. There are several factors affecting the charging efficiency of an EV, this includes temperature, state of charge (SOC), current, and voltage. Hence, this study is significant to investigate how these factors affect charging efficiency through methods of modelling and simulation. MATLAB Simulink has been selected as the tools and software adopted for performing modelling and simulation. A Constant Current Constant Voltage (CCCV) charging algorithm has been developed to simulate the charging of an EV battery, with the four factors affecting charging efficiency being the output of the model to establish a relationship with the charging time. Six different scenarios have been derived from the minimal and maximal optimal operating condition of the factors to observe the effects on charging efficiency. These scenarios are embedded within a MATLAB Function block in the form of MATLAB coding to determine the switching of charging phases. Upon running the simulation for the six scenarios, the results generated suggest that charging time is shorter when current input is greater. Whereas the charging time does not show significant changes when charging temperature increases. However, the cell temperatures were observed to increase when charging temperature and input current increases. The similarities observed from the results are that the charging speed at each SOC level is the same for the six scenarios. In summary, input charging current plays an important role in charging efficiency; temperature shows significant effect on battery and charging performance.