SPECIAL FEATURE
Vicor DC Regulation Vital to Success of Hydrogen Fuel Cell Power By Tom Williams, Contributing Editor The potential for hydrogen power in electric vehicles has been underestimated and certainly underpublicized. However, it actually has great potential—a potential that can profoundly change our technical and transportation environment. One misconception has been that such vehicles are powered by burning hydrogen. In reality, hydrogen is combined with oxygen in a controlled environment called a fuel cell to produce electricity and . . . water. The electricity, which manifests as DC current, is used to power the vehicles. Each hydrogen atom consists of one proton and one electron and exists in its gaseous form as H2. In the fuel cell, compressed hydrogen flows out of the secure storage tank where it meets a platinum grid where its electrons are separated and only the protons get through to cross through an electrolyte membrane and meet up with the O2 molecules in the
Figure 1: Conceptual diagram of a hydrogen fuel cell 20
COTS Journal | October 2021
air, which is brought in on the other side. The electrons are brought over via a conductor which they flow through in the form of electric current. On the other side, they can then combine with the protons from the hydrogen molecules and the oxygen atoms to form water. The current produced from the electron flow is used to power the vehicle (Figure 1). All major vehicle manufacturers are exploring hydrogen power and some even have products on the commercial market, albeit in extremely limited supply. In contrast, battery-powered EVs have progressed much further and major manufacturers have already announced huge investments and introduced product lines that are gaining popularity. Researchers in this arena, however, say that there will be no “winner” between hydrogen fuel cell vehicles and battery vehicles. Both will have a place in the transportation industry of the future.
Formerly, one of the biggest disincentives about hydrogen for powering vehicles has been its high volatility and nature as extremely explosive. This has led to a great deal of research and effort aimed at safe storage and has resulted in the development of tanks that are both relatively light-weight and are super strong. The current storage tank design consists of three layers: an inner plastic-lined layer of plastic-lined to prevent hydrogen leakage; a middle structural layer of carbon-reinforced plastic; and an outer glass-reinforced layer. They have been subjected to strenuous tests including crash tests, heating in fires over 800 degrees, and dropping from considerable heights. So far, only a direct hit from an armor-piercing bullet has been able to damage them enough to leak hydrogen. The weight-to-energy ratio along with the now well-developed safety has allowed the development of hydrogen-powered vehicles in addition to such things as robotic aerial drones and even hydrogen-powered big-rig trucks. Vicor is looking at an active role in the implementation of the DC power systems that control and distribute the electrical energy throughout such vehicles as all ranges of their functionality from drones to rail and ship transport. High-Density Conversion and Control for Drones and Beyond One of the characteristics of fuel cells is that their output can be highly variable and thus needs to be tightly controlled and regulated for use in real-world systems. Vicor Power has been working with Doosan Mobility Innovation to develop highly efficient and safe power systems for that company’s commercialized hydrogen fuel cell power pack that delivers breakthrough energy density, about 4 – 5 times that of a battery, enabling drones to
