Analysis of Battery State of Charge on the Condition of Acceleration and Regenerative Braking for Electrical Vehicle Using MATLAB

Abstract

The battery performance of electric vehicle (EV) is affected by the different driving condition, particularly during speed, acceleration and regenerative braking that also, it influences the energy consumption from the battery and its state of charge (SoC). The EV during its condition of acceleration and regenerative braking is analyzed based on the SoC using MATLAB simulation. Mathematical formulations of vehicle speed, acceleration, driving force, braking force, regenerative braking power, battery power, and SoC are developed for the EV model. It applies the technical parameters of EV Jaecoo J5 in the simulation, including a motor maximum power of 155 kW and battery capacity of 60.9 kWh with a time step of 0.1 s and a driving cycle time of 150 s. The results of simulation show that the vehicle speed and acceleration significantly affect the reduction of SoC and battery power. A higher energy consumption occurs at 20 s and 99.0 s for the battery power of 138.58 kW and 104.13 kW, respectively, where the condition causes the decreasing of SOC. Inversely, the battery power to be negative around -69.2 kW during the regenerative braking condition, it indicates that the energy recovery comes from the braking. The battery SoC decreases from its initial value of 80% to be around 77.11% at the end of the driving cycle, the condition illustrates that the motor needs and increases the energy consumption from the battery.