Ballard Power Systems (Germany)

Requirements for inertial response (IR) from wind turbines (WTs) have been implemented or drafted by power systems (PSs) operators worldwide. This is a response to the replacement of conventional power plants using synchronous generators by non‐synchronous, power electronics‐based generation and the resulting effect on frequency dynamics in the case of contingency events. The additional active power provided during operation in IR mode must be drawn from the rotating masses. A re‐acceleration accompanied by reduced active power output follows the activation phase. The allowed depth and duration of the post‐inertial recovery will be regulated in future versions of grid codes, e.g. in Québec and Ireland. This study describes an improved version of an IR control system that enables a more PSs‐friendly provision of such short‐term frequency support. The new controls allow adjusting the duration of the recovery period. Potential negative effects of IR from WTs on the PS in the form of a second frequency nadir during the recovery phase can be minimised. The outcome of simulations and of field testing will be presented. All results shown in this study include the initial and the future inertia emulation performance which allows easy comparison of the two controls.

Encapsulation of Pt nanoparticles (NPs) in a zirconia nanocage by area-selective atomic layer deposition (ALD) can significantly enhance both the Pt stability and activity. Such encapsulated Pt NPs show 10 times more stability than commercial Pt/C catalysts and an oxygen reduction reaction (ORR) activity 6.4 times greater than that of Pt/C.

CeOx is an excellent free radical scavenger to improve polymer electrolyte membrane durability. However, this metal oxide will dissolve during accelerated stress testing (AST), with the resulting cations transporting to the cathode catalyst layer (CCL) leading to performance reduction/degradation of the PEMFC. Controlling the rate of CeOx dissolution is therefore of great importance, as it may be possible to maintain sufficient Ce cations for free radical scavenging while minimizing the impact of these cations on the CCL. Here the effect of CeOx crystallite size on CeOx dissolution was investigated. Three CeOx additives were prepared having crystallite sizes of 6, 13, or 25 nm. An ex-situ method was used to evaluate the chemical stability of these three CeOx samples, as well as one commercially available CeOx. It was determined that surface area, rather than crystallite size, is the best predictor of chemical stability. In-situ membrane electrode assembly AST cycling was then performed, demonstrating that when low loadings of CeOx (0.006 mg/cm2) are used, the ex-situ method correctly predicts trends in end of life (EOL) performance. Finally, it is shown that increasing the anode RH during AST cycling leads to significantly higher EOL performance losses.

Nitrogen-doped graphene as a metal-free catalyst for oxygen reduction was synthesized by heat-treatment of graphene using ammonia. It was found that the optimum temperature was 900 °C. The resulting catalyst had a very high oxygen reduction reaction (ORR) activity through a four-electron transfer process in oxygen-saturated 0.1 M KOH. Most importantly, the electrocatalytic activity and durability of this material are comparable or better than the commercial Pt/C (loading: 4.85 µgPt cm−2). XPS characterization of these catalysts was tested to identify the active N species for ORR.

New regulations mandated by the FCC would require telecommunications operators to assure a minimum backup power capacity at every site to improve availability of communications networks, especially during emergency situations. This paper explores the implications of the new Katrina panel order and its associated backup power rule within the context of mobile telecommunications infrastructure. Operators can choose among a variety of technologies to implement the required backup capacity at cellular base station sites. Fuel cell generators can help overcome some of the challenges to meet compliance with the new FCC rule.

<div class="htmlview paragraph">The main issues related to the vibration response and acoustic noise emission of a new liquid fuelled fuel cell APU (auxiliary power unit) system are discussed and analyzed. These problems are being addressed in an on-going research project. The APU is comprised of several critical subsystems including the fuel processing system, fuel stack, heat exchanger, compressor, as well as high-pressure and low-pressure components. The vibration concern deals with the design of a two-stage isolation mount system to shield these critical parts from the shock and steady-state dynamics coming through the truck frame during on-road traveling conditions. A lumped parameter dynamic model is formulated for use in optimizing the mount stiffnesses and locations. Acoustic concerns are primarily related to exterior noise levels when the truck is at a rest stop. To address those issues, experimental studies are conducted to quantify the main sources and paths for noise. The measured results are used to develop effective noise control measures to tackle not only the broadband dominated loudness but also the tonal characters of the signals.</div>