Integrated CMOS Energy Harvesting Converter With Digital Maximum Power Point Tracking for a Portable Thermophotovoltaic Power Generator

Abstract

Abstract-This paper presents an integrated maximum power point tracking system for use with a thermophotovoltaic (TPV) portable power generator. The design, implemented in 0.35 µm CMOS technology, consists of a low-power control stage and a dc-dc boost power stage with soft-switching capability. With a nominal input voltage of 1 V, and an output voltage of 4 V, we demonstrate a peak conversion efficiency under nominal conditions of over 94% (overall peak efficiency over 95%), at a power level of 300 mW. The control stage uses lossless current sensing together with a custom low-power time-based ADC to minimize control losses. The converter employs a fully integrated digital implementation of a peak power tracking algorithm, and achieves a measured tracking efficiency above 98%. A detailed study of achievable efficiency versus inductor size is also presented, with calculated and measured results.

A Modified Firefly Algorithm for Photovoltaic Maximum Power Point Tracking Control Under Partial Shading

“…However, the connection of bypass diodes will change the uniform current-voltage (I-V) and power-voltage (P-V) characteristics of the module, resulting in multiple peaks [1]. To maximize the efficiency of the module, it is necessary to track The conventional MPPT methods such as perturb-and-observe (P&O) [2], [3], hill-climbing (HC) [4] and incremental conductance (INC) [5] essentially rely on determining the gradient of the power with respect to the current, voltage or duty cycle using the perturbation method for tracking movement [6]. Consequently, the main drawback of these methods is that they cannot differentiate between a local maximum point (LMP) and the GMP, and the attained point may be a LMP, leading to power losses.…”

A CMOS-Based Energy Harvesting Approach for Laterally Arrayed Multibandgap Concentrated Photovoltaic Systems

“…For control loss minimization, a perturband-observe (P&O) algorithm is developed here that enables perturbation of each of the input duty cycles for MPPT while only requiring power sensing at the output, without explicit current measurements. This technique generalizes upon the approach introduced in [25] to handle multiple-input MPPT as required here. Fig.…”

“…However, even measuring a single current can incur loss, as it typically requires sensing the voltage across a known resistance inserted into the current path. A technique is thus selected for equivalent current sensing without extra losses, leveraging the parasitic equivalent series resistance of the inductor (R ESL ), similar to the approach proposed in [25]. As shown in Fig.…”

Asymmetric interleaving in low-voltage CMOS power management with multiple supply rails

“…In the case of solar photovoltaics, a variance in radiance conditions and module characteristics results in each sub-module operating at different conditions in order to achieve maximum power point tracking [33,34,35,36].…”