A logarithmic term is applied to account for the charge transfer overvoltage with most empirical polarization curve fitting equations for polymer electrolyte membrane fuel cells. The logarithmic term applied with state-of-the-art fitting equations is proportional to the logarithm of the cell output current density. This provides good fitting characteristics with large current densities, but res...

Original scientific paper The increasing sensitivity of electronic devices widely used in low-voltage AC systems requires an appropriate protection against voltage and current surges. Protection of the equipment against the prospective surges is based on application of surge protection devices (SPDs). Most common situation, especially in residential buildings, is application of only one SPD at ...

Electron channeling effects can create measurable signal intensity variations in all product signals that result from the scattering of the electron beam within a crystalline specimen. Of particular interest to the X-ray microanalyst are any variations that occur within the characteristic X-ray signal that are not directly related to a specimen composition variation. Many studies have documente...

Proton exchange membrane fuel cells (PEMFC) have been increasingly applied in clean and efficient distributed power generation systems recent years. However, the output characteristics of PEMFC are relatively soft due to influence multiple polarization overvoltage. With increasement current density, voltage shows be a nonlinear downward trend. In addition, order ensure lifetime PEMFC, ripple is...

High Voltage Direct Current (HVDC) systems are increasingly being adopted around the world to integrate renewable resources, increase power transfer, and allow flexible grid operation. HVDC overhead lines play a critical role in this, focus is needed on research of composite outdoor insulators failure. In case pole ground fault bipolar scheme, healthy experiences slow transient overvoltage simi...

With the rapid development of wide-band gap semiconductor chip and package technologies, voltage class commercial silicon carbide (SiC) device is gradually improved. This paper concentrates on latest 3.3-kV full SiC-based metal oxide field-effect transistor (MOSFET) its application in railway traction. First, compared with Si-based insulated-gate bipolar (IGBT), MOSFET shows lower switching los...

Abstract Breakdown voltage (BV) is arguably one of the most critical parameters for power devices. While avalanche breakdown prevailing in silicon and carbide devices, it lacking many wide bandgap (WBG) ultra-wide (UWBG) such as gallium nitride high electron mobility transistor existing UWBG due to deployment junction-less device structures or inherent material challenges forming p-n junctions....

The Dynamic Voltage Restorer (DVR) is a commercially available, popular device to eliminate voltage sags and swells in the distribution lines. Its basic function is to inject the voltage difference (difference between the pre-sag and sag voltage) to the power line and maintains the pre-sag voltage condition in the load side. The efficiency of the DVR depends on the performance of the efficiency...

In this study, we replaced the expensive blade material with an aluminum-bronze alloy that has excellent corrosion resistance and cavitation characteristics and developed the corrosion protection method to improve durability using an electrochemical method. The objective of this study was to identify the electrochemical corrosion protection conditions to minimize cavitation damage due to genera...