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This paper introduces a new capacitive wireless power transfer approach with the potential to significantly enhance power transfer density in large air-gap applications. This enhancement is achieved through the use of multiple phase-shifted capacitive plates that reduce fringing fields in areas where field levels must be limited for safety reasons. The effectiveness of the proposed approach is evaluated using an analytical framework and validated using finite-element and circuit simulations. It is shown that a 6.78-MHz eight plate-pair system based on the proposed approach reduces fringing fields by a factor of five relative to a two plate-pair system while retaining the same power transfer density.Index Terms -Wireless power transfer, capacitive power transfer, modular architecture.

Performance of bulk Si based solar photovoltaic (PV) panels deteriorate in weak light conditions. This generally affects the efficiency of associated power electronic components and compounds the overall loss in the yield of a PV system. It is, therefore, imperative to carefully plan the PV sizing and quantify this inherent loss in the efficiency of PV panels. In this work, the impact of varying solar irradiation on the efficiency of crystalline Si based solar panels has been quantified through a novel mathematical formulation, which models the deterioration in performance based on actual insolation and temperature profiles. This loss phenomenon is attributed mainly to a reduction in open circuit voltage and fill factor of a panel which in turn lowers the conversion efficiency. An empirical relationship is also derived which relates the loss in energy harvested to the actual peak-sunlight hours of a region. Results indicate that this low irradiance loss has approximately a linear dependence on equivalent peak sunlight hours (EPSH). For instance, the loss of 3.8%, 4%, 4.5% for Austin, Washington and Seattle was observed for EPSH of 4.4, 4, and 3.4, respectively. Moreover, the loss variation from one year to another for a region has been approximately constant. Finally, a comparison was performed for predicted energy harvested to the measured yield and a good fit has been observed between predicted and actual values.

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