A reconfigurable battery system for a Tesla Model Y: Package and efficiency analysis

This study investigates the integration of a modular multilevel inverter-based reconfigurable battery system into an existing electric vehicle. The aim is to evaluate how such systems can replace conventional traction inverters, battery management systems, and on-board chargers. To this end, a classification of the different topology levels and possible forms of integration of power electronics, control logic, and driver electronics is performed. A Tesla Model Y’s traction battery is redesigned, retaining its structural properties and the 4680 cell format. A package analysis shows that the multilevel system occupies a volume comparable to the conventional battery pack, while the volume previously reserved for dedicated power electronics becomes available. Efficiency simulations demonstrate that the multilevel inverter can increase the overall vehicle efficiency, especially in situations with low driving speeds and high torque requirements. As a result, WLTP energy consumption is reduced from 14.9 kWh/100km to 14.5 kWh/100km. However, the battery efficiency is reduced at higher speeds due to higher cell currents. In addition, the system enables bidirectional charging at full system power, including supply to external loads or the grid, and a more integrated vehicle architecture. • Packaging a reconfigurable battery system in a production electric vehicle is possible. • Battery pack volume houses cells and new inverter, freeing up junction box space. • On-board charger can be omitted due to intrinsic high power bidirectional charging. • WLTP energy consumption (excluding charging lossess) is reduced from 14.9 kWh/100 km to 14.5 kWh/100 km. • Inverter losses decrease by up to 76 % at low vehicle speed and high torque.