In order to meet customers’ requirements and their power needs, we have developed means for combining our fuel cell assemblies, electrically in series and parallel, to scale towards the required output power and voltage level of the customer application. In this blog, we have asked one of our fuel cell engineers, Lan Hu, PhD, to cover our way of connecting our fuel cell assemblies.
The nominal voltage when operating an individual fuel cell is 0.6-0.7V at nominal operation and we bring several cells in series together to allow for the use of high efficiency electronics implementations and control of a single fuel cell assembly. High efficiency is important to get maximal power output and optimal operational conditions.
In order to achieve a customers required system power we scale by adding fuel cell assemblies. To efficiently achieve the voltage level used in the customer’s system we can add fuel cell assemblies in series similar to how battery packs are built from battery cells. When fuel cell assemblies are connected in series it implies that the same current flows through them all. For this reason, we have developed highly efficient electronics that allow that while still maintaining the proper operational conditions for the individual fuel cells.
Our versatile designed fuel cell assembly and associated electronics enable them to be operated rather independently while still being combined in parallel or in series.
For individual cells connected in series: The active cell area and number of cells are vital parameters when designing fuel cells connected in series. The current depends on the amount of gas reactants (hydrogen and oxygen or air) and the active cell area, and the voltage depends on the number of cells connected in series of the fuel cell assembly.
For fuel cell assemblies connected in series, the gas flow distribution and temperature profile are important parameters to manage to enable optimal operation conditions and high efficiency output power.
Our ability to combine our fuel cell assemblies constitutes the fundament of our modular design enabling us to build solutions to fit not only the customers power need and voltage level requirement, but also allow for an application specific physical integration into available space and volume. We call all this freedom-in-design.