Experimental Investigation of Battery Current Dynamics in Grid-Connected Electrical Vehicles

The transition towards sustainable transportation necessitates a thorough understanding of the interaction between Electric Vehicles (EVs) and the distribution grid, especially concerning environmental and sustainability challenges. One critical aspect of this interaction is the behaviour of battery current during the charging and discharging processes. This paper analyses the battery current characteristics in a grid-integrated EV system powered by lithium-ion batteries. The system includes critical components such as a Battery Management System (BMS), a bidirectional propulsion drive, a DC-DC converter (rated at 2.3 mH and 40A), an induction motor for propulsion (3.5/3 kW), and a front-end converter (FEC) integrated with a load emulator. Through experimental investigation, the study reveals significant findings regarding the relationship between reference torque and motor operation modes. Positive reference torque corresponds with the induction machine’s motoring mode, while the propulsion motor’s regenerative mode correlates with energy recovery during deceleration. A critical observation is the impact of abrupt speed variations, which lead to rapid battery depletion. These effects are closely examined under different operational scenarios, providing valuable insights into the dynamics of EV systems. The results highlight the importance of understanding battery behaviour in real-time conditions, which is essential for optimizing EV performance and enhancing grid integration.