Publications

Results 126–150 of 151
Skip to search filters

Sensitivity analysis of a technique for the extraction of interface trap density in SiC MOSFETs from subthreshold characteristics

IEEE International Reliability Physics Symposium Proceedings

Hughart, David R.; Flicker, Jack D.; Atcitty, Stanley A.; Marinella, M.J.; Kaplar, Robert K.

A method for extracting interface trap density (DIT) from subthreshold I-V characteristics is used to analyze data on a SiC MOSFET stressed for thirty minutes at 175°C with a gate bias of-20 V. Without knowing the channel doping, the change in DIT can be calculated when referenced to an energy level correlated with the threshold voltage. © 2014 IEEE.

More Details
TYPE Conference YEAR 2014
ScopusOSTIDOI

Photovoltaic ground fault and blind spot electrical simulations

Flicker, Jack D.; Johnson, Jay

Ground faults in photovoltaic (PV) systems pose a fire and shock hazard. To mitigate these risks, AC-isolated, DC grounded PV systems in the United States use Ground Fault Protection Devices (GFPDs), e.g., fuses, to de-energize the PV system when there is a ground fault. Recently the effectiveness of these protection devices has come under question because multiple fires have started when ground faults went undetected. In order to understand the limitations of fuse-based ground fault protection in PV systems, analytical and numerical simulations of different ground faults were performed. The numerical simulations were conducted with Simulation Program with Integrated Circuit Emphasis (SPICE) using a circuit model of the PV system which included the modules, wiring, switchgear, grounded or ungrounded components, and the inverter. The derivation of the SPICE model and the results of parametric fault current studies are provided with varying array topologies, fuse sizes, and fault impedances. Closed-form analytical approximations for GFPD currents from faults to the grounded current carrying conductor-known as %E2%80%9Cblind spot%E2%80%9D ground faults-are derived to provide greater understanding of the influence of array impedances on fault currents. The behavior of the array during various ground faults is studied for a range of ground fault fuse sizes to determine if reducing the size of the fuse improves ground fault detection sensitivity. The results of the simulations show that reducing the amperage rating of the protective fuse does increase fault current detection sensitivity without increasing the likelihood of nuisance trips to a degree. Unfortunately, this benefit reaches a limit as fuses become smaller and their internal resistance increases to the point of becoming a major element in the fault current circuit.

More Details
TYPE SAND Report YEAR 2013
OSTIDOI
Results 126–150 of 151
Results 126–150 of 151