A fuel cell was first invented in 1839. Since then many works have been done and fuel cells will be really commercialized in the fields of stationary uses, electric vehicles and mobile applications in the near future. Considering the world climate change due to the large consumption of fossil fuels, we have to create a clean energy system as soon as possible. The hydrogen energy system would be the best energy system against the global warming. In order to utilize the hydrogen energy, fuel cell systems are most suitable. The development should be encouraged much more in the worldwide scale.

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Anode performance of nickel (Ni) - scandia stabilized zirconia (ScSZ) cermet, Ni- samaria doped ceria (SDC) cermet and 1 vol% of SDC finely dispersed Ni-ScSZ cermet (SD-Ni-ScSZ) was examined at 1073 K with hydrocarbon fueled solid oxide fuel cells (SOFCs) consisting of a ScSZ electrolyte and a Ni mesh current collector. At least two anode reaction processes were observed in the impedance spectra for all tested anodes. The one corresponding to the high frequency region was enhanced in the order of the Ni-ScSZ, SD-Ni-ScSZ and Ni-SDC, whereas that observed in the low frequency region seemed to be retarded in the same order. The effect can be ascribed to changing Ni surface state by SDC component in the anode. The SD-Ni-ScSZ anode shows the best performance; that shows the smallest overall anodic resistance and the highest hydrogen content in the outlet gas under the same fuel utilization operation among the tested anodes.

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Plasma surface treatment is an optional way to change the electrical performance of the film capacitors used widely in pulse power application. This paper presents the experimental study of glow discharge plasma treatment to polyphenylene sulfide (PPS) film. By using infrared spectra and scanning electron microscope (SEM), the chemical component and microstructure of material surface has detected to be changed with different treatment strength and various discharge gas. After treatment, the film surface tends to be rougher and some sorts of polar radicals or groups found to be introduced. But there is no obvious change of the electrical strength of the film. At last, theoretical analysis has been carried out with polypropylene film experimental treatment results in author's former work.

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The purpose of this study is to clarify effects of three-dimensional phenomena on performance of the Magnetohydrodynamic (MHD) accelerator for the MAPX project at NASA Marshal Space Flight Center. Generally, in a Faraday type of MHD accelerator with segmented electrode, high flow velocity augmentation can be achieved. However, many independent power supplies have to be installed. A diagonal type of MHD accelerator requires only one power supply, and it is hopeful for the practical applications. Hall current neutralized condition was proposed in this study where each electrode pair was linked externally so as to cancel the current caused by the Hall effect. Results showed that the diagonal accelerator with the neutralized condition could achieve an outlet velocity equivalent to that in the Faraday accelerator. The axial velocity augmented from 1235m/s at inlet to 3040m/s at the outlet under the 300Amps of load current. It is found that the neutralized condition was not implemented in a whole of the cross section when there was plasma non-uniformity. The Lorentz force due to the current concentration caused the velocity-overshoot and the secondary flows. This study of the 3-D analysis provided prediction of the plasma behavior in an MHD accelerator channel as prior numerical analysis for the MAPX project carried out at NASA Marshall Space Flight Center.

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It is very important to discriminate noises such as air corona in measuring on-site partial discharges (PD). Therefore, in order to investigate the possibility of separating PD and noises through the pulse wave shape analysis (PWA), pulse wave shapes measured by a resistive sensor and a high frequency current transformer (HFCT) have been analyzed and PWA were performed. For the purpose, the high frequency partial discharge (HFPD) detection and PWA system has been developed. Also void discharges and air corona were adopted as the artificial defect and noises, respectively. For the PWA algorithm, two kinds of methods such as TF-KK (Kurtosis of time domain and frequency domain) and MMR-S (the ratio of max/min value and the summation of the captured data) were compared. As a result, the developed system in this study showed good ability of distinguishing small void discharges from very large noises such as big air corona and ground floating discharges, which implies that the developed HFPD diagnostic system with the PWA algorithm has been proved to have very good performance of eliminating noises.

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High voltage equipments, especially polymer insulators may be getting into aging conditions due to the existence of corona discharge on the surface after a long term of running, which would accelerate the deterioration of the surface insulation performance, and even make equipments step into calamity ultimately. So it is significant to detect corona discharge on surface to ensure insulators' stable running. This paper presents the development of a novel corona discharge detection system based on photomultiplier tube (PMT), which has good functions of distance detection for corona discharge in determined region from surface of high voltage equipment and corona characteristics data analysis. In the verification experiments, it was shown that UV corona light can be also taken as characteristic for detecting corona discharge, other than corona leakage current detection, and a linear relationship was shown between the light magnitude and the current magnitude. Furthermore, mean peak value and number of pulses whose peak value is above threshold are extracted from the basic data, which can be used to quantify the development of corona discharge. The results of investigation on polymer insulators suggested that detection of the region between metal end fitting and first shed should be emphasized. The measurements of corona discharge distribution along insulators can be used to learn about the degradation conditions. Detection of polymer insulators in lab and field inspection experience are both soundly verifying the usefulness of the corona detection system.

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