Lossless Digitally-Assisted Windowed Current Sensing for Solar Photovoltaic Applications

Abstract

Sensing current across a sense resistor adds to the total power loss and decreases efficiency. This work demonstrates the use of a current sense amplifier that measures current across a length of wire so as to minimize power loss. Current Sense Amplifiers for solar photovoltaic applications require measuring a wide range of current (e.g. 1-10A), yet a high resolution is needed for certain applications such as maximum power point tracking (MPPT) and differential power processing (DPP). The windowing technique has been adopted in this work, so as to measure the current with high resolution and yet to be able to cover the entire range of current as well. The use of PSOC 4 by Cypress offers a cost effective one chip solution to all current sensing requirements for solar photovoltaic applications. This is achieved by having a nearly $4 cost reduction from previous methods, and yet attaining under 1% error in current measurements.Ope

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