A 5.5W-to-276W Integrated Photovoltaic Energy Harvesting System with 99.95% MPPT Efficiency and 98.74% Power Conversion Efficiency

초록

A high-efficiency integrated photovoltaic (PV) energy harvesting system based on direct current resistance (DCR) current sensing is proposed. The system employs an integrated microcontroller unit (MCU) to precisely control a high-voltage gate driver, which drives the power field-effect transistor based on sensed instantaneous voltage and current information. Power conversion efficiency is enhanced through DCR current sensing for instantaneous power computation and by achieving low on-resistance of external power field-effect transistors via high-voltage gate driver control. The MCU orchestrates sophisticated timing control between the high-voltage gate driver, sample and hold circuit, and a 12-bit analog-to-digital converter to sense inductor current, thereby achieving high tracking efficiency. The integrated circuit for the PV energy harvesting system is fabricated using 0.13 μm BCD process and operates over a wide power range from 5.5 W to 276 W. Thanks to the DCR current sensing network and precise power sensing, the system achieves a high tracking efficiency of over 99% across the power range of 11.7 W to 276 W, demonstrating exceptional stability. The system achieves a peak tracking efficiency of 99.95% and a peak power conversion efficiency of 98.74%, representing the highest efficiency and power density compared to state-of-the-art PV energy harvesting systems. © 1986-2012 IEEE.

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