Pre-energized compact auxiliary circuit to buffer loads from fast transients with the goal of managing load-informed power

A pre-energized auxiliary circuit can be constructed to buffer fast load transients using advance information from an intelligent load. Such information should include the exact times of load transients and their magnitudes. This paper proposes a compact auxiliary circuit that generates a current half the magnitude of the transient. The proposed circuit builds on earlier work addressing load-informed power and operates to pre-energize the power supply. The goal is to integrate it with an intelligent load. © 2013 IEEE.published_or_final_versio

Hot spotting and second breakdown effects on reverse I-V characteristics for mono-crystalline Si photovoltaics

Hot spots are a common problem in photovoltaic (PV) panels that accelerate cell degradation and reduce system performance. Hot spots occur when a cell is reversed biased, sinks power, and heats the cell. At a certain threshold, the PV p-n junction goes into second breakdown and heats a small portion of the cell to very high temperatures. This study experimentally tests mono-crystalline Si cells as they hot spot at different power levels. Heating effects on the I-V characteristics during hot spotting and permanent changes after seven days of hour-long hot spot tests are observed and analyzed. I-V characteristics are significantly affected under second breakdown, which is observed when cells are reverse-biased above two times the rated maximum power level