Band 7, Heft 2

Typical thermoelectric generator legs are brittle which limits their application in vibratory and shear environments. Research is conducted to develop compliant thermoelectric generators (TEGs) capable of converting thermal loads to power, while also supporting shear and vibratory loads. Mathematical structural, thermal, and power conversion models are developed. Topology optimization is employed to tailor the TEG design yield maximal power production while sustaining the applied shear and vibratory loads. As a specific example, results are presented for optimized TEG legs with a void volume fraction of 0.2 that achieve compliance shear displacement of 0.0636 (from a range of 0.0504 to 0.6079). In order to achieve the necessary compliance to support the load, the power reduction is reduced by 20% relative to similarly sized void free TEG legs.

This article investigates piezoelectric materials for harnessing vibrational energy. A nano hollow cylindrical structure based on various piezoelectric materials was designed and utilised to generate the voltage. An accurate and efficient model is developed here, so as to optimized the efficiency of the piezoelectric energy harvester. This work analyses the piezoelectric actuator deflection and involves the Eigen frequency computation. A measurement methodology for investigating the mechanical and electrical behaviour of vibrational harvester's was modelled and analysed by finite element method using COMSOL software. The energy harvesting structure was developed and tested with different piezoelectric materials to attain appreciable voltage through a small deflection. The Simulated results predicts that for the same pressure range, different piezoelectric materials have the different output voltage and Eigen frequencies. The maximum voltage was observed for Barium Titanate (3.0847 V at 250 µm), along with poled Polyvinylidene fluoride. In addition, a comparison was made with different piezoelectric materials ideally suited to intelligent cantilever structure. For optimizing the performance of the piezoelectric energy harvester an accurate and efficient model is required, which was developed in this simulation study. A high voltage value with a small deflection through a cylindrical hollow structure was designed and tested using various piezoelectric materials in this study.

Renewable energy sources are receiving wide popularity due to the shortage of fossil fuels and environmental problems caused by conventional energy sources. Solar photovoltaic energy is a widely used sustainable energy source. The power developed by a solar cell is greatly influenced by the insolation level. Partial shading occurs when one or more photovoltaic (PV) cells receive lesser radiation as compared to other cells, which in turn affects the overall electrical performance of PV cells including reduced generated power. This paper proposes a newly developed configuration known as Reformed-Total cross-tied (R-TCT) to improve the power generation during partially shaded conditions in small-scale PV systems, especially for urban and rural area applications. The basic idea of this paper is to redistribute the shaded modules of a row to other rows such that the number of shaded solar PV modules of each row are nearly same. The proposed method is validated by simulation and also by hardware implementation. The simulations and experiments are done on eight different shading cases and found that the proposed method gives either superior or same performance as that of existing TCT, LS (Latin Square)-TCT, and D-TCT configurations.