Flexible Power Take-off Unit for Fuel Cell Electric Vehicles

As medium-duty vehicles for commercial and industrial applications shift from diesel fuel to fuel cells as a source of power, electric power take-off systems are needed to replace the engine-driven power take-off systems used for auxiliary applications requiring hydraulic, pneumatic, mechanical and electrical power. An electric power take-off system converts the electricity produced by the fuel cell for the transportation drive system to voltages used by auxiliary equipment. This proposal offers a solution compatible with fuel cells from a variety of vehicle models and manufacturers and provides capability to convert that power for use with diverse equipment and loads. The resulting product will offer a step-function improvement in efficiency and the air-cooled design will yield higher reliability for greater return on investment. The objective of this project is to design an electric power take-off system capable of accepting a voltage input from 300 volts to 900 volts from any fuel cell electric vehicle. The electric power take-off system will convert the fuel cell output to supply alternating current power in the 5-10 kilowatt range at common industry voltages such as 120- and 240-volt single-phase, or 208- and 480-volt three-phase. This approach makes the exported power compatible with a wide range of motors, pumps and other auxiliary equipment with continuous loads up to ten horsepower. The Phase I project scope of work includes the custom design and simulation of an isolated converter with dual active bridge topology, a lightweight high-frequency transformer design, an effective cooling system and a proprietary adaptive power electronics control system to meet the strict efficiency and size requirements for the application. The work scope also includes identifying a commercially available inverter for the output of the electric power take-off system. Further, Phase I includes planning for systems integration, manufacturing readiness analysis, and commercialization work to position the system for full-scale prototype development in Phase II. Additionally, the system is well-suited to deliver mobile and job-site power requirements. Traditionally, power equipment such as compressors, welders, saws and lights at job-sites have been powered by gasoline and diesel generators, or by standalone batteries. The electric power take-off provides an efficient, clean and affordable alternative to portable generators and batteries, while leveraging the return on investment of the fuel cell incorporated in the electric vehicle. Energy consumption for vehicle equipment and job-site loads may be halved by using power produced by fuel cells due to much higher efficiency than internal combustion engines. Further, with zero site emissions, the proposed technology benefits the public as a whole by reducing particulate and greenhouse gas pollution, and the electric power take-off is ideal for work being conducted in delicate ecosystems.