How power electronics will empower the future of mobility: Part 2

Power electronics convert and control electric power in vehicles, ensuring optimal performance and efficiency. By managing power use, they enable longer distances, reduce energy waste and support sustainable transportation.

In Part 1, we explored the role of power electronics in battery electric vehicles (BEVs). This article focuses on their role in fuel cell electric vehicles (FCEVs), highlighting their advantages and Cummins Inc.’s commitment to advancing environmentally responsible transportation.

Power electronics in fuel cell electric vehicles

Fuel cell electric vehicles (FCEVs) use hydrogen to generate electricity, powering the motor. The fuel cell stack splits hydrogen into protons and electrons, with the electrons traveling through an external circuit to generate electricity.

FCEVs share power electronics with battery electric vehicles (BEVs) but include additional components to meet their specific needs. A key component is the boost DC-DC converter, which raises the voltage from the fuel cell stack to match the higher voltage required by the battery system. FCEVs also include a smaller battery that stores energy from the fuel cell, providing extra power during high-demand situations like acceleration. This hybrid system reduces fuel cell response time, improving safety, performance, and drivability.

Power electronics for fuel cell efficiency in heavy-duty transportation

Fuel cells offer key advantages for transportation, particularly in heavy-duty applications. Hydrogen's high energy density enables quick refueling (about 20 minutes) and long driving ranges, making it an ideal alternative to diesel for sectors requiring minimal downtime and long distances.

Fuel cells operate at lower voltages (200-600V), necessitating components like the Boost DC-DC converter to step up voltage for efficient energy transfer and battery charging. This compatibility allows FCEVs to use the same battery and power electronics as BEVs, simplifying manufacturing, reducing costs, and enhancing scalability.

Integration of power electronics in fuel cell systems

As fuel cells age, their voltage output decreases, requiring higher current to maintain power, which can lead to energy losses and excess heat. Power electronics regulate voltages and currents to mitigate these issues. The use of silicon carbide in power semiconductors reduces energy loss and improves thermal management, essential for maintaining performance at higher temperatures.

Advancements in technology are enabling broader adoption of FCEVs, especially in sectors like heavy-duty trucking and stationary power generation. As hydrogen infrastructure expands, FCEVs will play a pivotal role in sustainable transportation, supporting efforts to reduce carbon emissions and fossil fuel dependency.