Porsche Engineering Presents Advanced AC Battery System for EVs

Porsche Engineering introduces a modular AC battery concept for EVs, combining battery management, inverter, and charger in one unit. Learn more about this innovation.

Porsche Engineering has introduced an innovative concept that could redefine electric vehicle architecture—the AC battery. This advanced system integrates the battery management unit, inverter, DC/DC converter, and onboard charger into a single unit, streamlining the powertrain design.

In traditional electric vehicles, high-voltage batteries, power electronics, inverters, and charging units function as separate components. While this setup has proven reliable, Porsche engineers believe there is potential for improvement. According to Thomas Wenka, a Specialist Project Manager at Porsche Engineering, the industry is shifting toward highly integrated components to reduce size, weight, and cost while enhancing reliability and efficiency.

As part of a feasibility study, Porsche divided the battery pack into 18 individual modules, distributed across three phases, each managed by semiconductor switches. This Modular Multilevel Series Parallel Converter (MMSPC) allows direct generation of three-phase AC voltage from the battery without a conventional inverter. It also enables the vehicle to connect directly to the AC grid for charging.

The MMSPC architecture provides several key benefits, including enhanced safety and failure management. In case of an accident or maintenance operation, the system can safely disconnect, reverting to individual module voltage levels. Additionally, its intelligent control system can bypass faulty cells, activating a limp-home mode—something traditional batteries lack.

At the core of the AC battery is a high-performance, real-time computing platform based on a heterogeneous multiprocessor system, combining a system-on-chip module with FPGA technology. This configuration not only ensures precise and dynamic battery module control but also allows for scalability from basic Electronic Control Units (ECUs) to more complex Advanced Driver Assistance Systems (ADAS). The FPGA handles complex calculations and supports dynamic reconfiguration through software, making the system highly adaptable for various applications.

The AC battery concept has undergone successful bench tests and has been integrated into a test vehicle to validate its viability. Porsche Engineering has also developed a new modular control unit platform, which supports the AC battery’s functionality and has been designed with future adaptability in mind. Although the system remains in the prototype stage, it has the potential for further refinement and possible adaptation for production vehicles with minor modifications.

While no commercial rollout has been announced, the AC battery's integration capabilities, enhanced safety features, and potential for high-speed charging position it as a promising innovation for the next generation of electric vehicles.

Source: porsche.com