Influence of Power Conditioning on the Optimization of Energy Harvesting Systems

2009 ◽  
Author(s):  
Stephen G. Burrow ◽  
Lindsay R. Clare
Keyword(s):  
Energy Harvesting ◽  
Peak Power ◽  
Electrical Power ◽  
Building Blocks ◽  
Load Resistance ◽  
Maximum Power ◽  
Power Conditioning ◽  
Harvesting Systems ◽  
Converter Topology ◽  
Power Point

Energy harvesting systems have components in both mechanical and electrical domains and in order to optimize the design of the overall system, the effect of practical electrical power conditioning sub-systems on the mechanical operation of the harvester must be taken into account. From basic considerations of a linear energy harvester it is shown that, for optimum mass displacement, the effective load resistance presented to the harvester by the power conditioning circuitry should be equal to or less than the load resistance at the peak power point. Further consideration reveals that peak power per volume may occur at an operating point different to that at which maximum power is achieved. The commonly available building blocks of the power conditioning system have characteristics that make it impossible to operate the harvester in a stable manner in the optimum region, and more complex techniques of maximum power tracking may consume excessive quiescent power and are only valid if maximum power is required at all times. The discussion is illustrated by numerical simulations. Finally a converter topology is described and realized, using discrete components, that goes some way to addressing these issues.

scholarly journals Influence of Parasitic Resistances on the Input Resistance of Buck and Boost Converters in Maximum Power Point Tracking (MPPT) Systems

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1464
Author(s):  
Marcin Walczak ◽  
Leszek Bychto
Keyword(s):  
Input Resistance ◽  
Load Resistance ◽  
Maximum Power ◽  
Solar Panels ◽  
Maximum Power Point ◽  
Boost Converters ◽  
Pv Systems ◽  
Point Tracking ◽  
Pv Panel ◽  
Power Point

DC/DC converters are widely used in photovoltaic (PV) systems to maximize the power drained from solar panels. As the power generated by a PV panel depends on the temperature and irradiance level, a converter needs to constantly modify its input resistance to remain at the maximum power point (MPP). The input resistance of a converter can be described by a simple equation that includes the converter load resistance and the duty cycle of the switching signal. The equation is sufficient for an ideal converter but can lead to incorrect results for a real converter, which naturally features some parasitic resistances. The goal of this study is to evaluate how the parasitic resistances of a converter influence its input resistance and if they are relevant in terms of MPPT system operation.

scholarly journals Comparison of solar power measurements in alpine areas using a mobile dual-axis tracking system

2019 ◽  
Vol 2 (S1) ◽  
Author(s):  
Jelenko Karpić ◽  
Ekanki Sharma ◽  
Tamer Khatib ◽  
Wilfried Elmenreich
Keyword(s):  
High Altitude ◽  
Peak Power ◽  
Power Plants ◽  
Low Cost ◽  
Elevation Angle ◽  
Test Site ◽  
Maximum Power ◽  
Maximum Power Point ◽  
Photovoltaic Power ◽  
Power Point

Abstract The rising demand for sustainable energy requires to identify the sites for photovoltaic systems with the best performance. This paper tackles the question of feasibility of photovoltaic power plants at high altitude. A direct comparison between an alpine and an urban area site is conducted in the south of Austria. Two low-cost automatic photovoltaic power measurement devices with dual-axis sun tracking and maximum power point tracking are deployed at two test sites. The system periodically performs a scan over the southern semihemisphere and executes maximum power point adjustment in order to assess the performance for a given direction. The gathered data shows a higher photovoltaic power yield in the higher altitude test site. Furthermore, the high altitude photovoltaic power as a function of azimuth and elevation angle appears to be not only higher but also more flat than in lower altitudes. This indicates a lower power loss in case of deviation from the optimal solar angles. The results show that even on low-cost hardware a difference in photovoltaic power can be observed, even though in this experiment it amounts to less than 5% increase of peak power in higher altitudes. However, the measured peak powers on the mountain are more stable and therefore closer to a constant level than the heavily fluctuating peak power values at the low altitude site. Additionally, a slight shift in optimal elevation angles between altitudes can be observed, as the optimum angle turns out to be lower on the high altitude site. This angle shift could be caused by snow reflections on the mountainous test site.

scholarly journals Electrical power management and optimization with nonlinear energy harvesting structures

2018 ◽  
Vol 30 (2) ◽  
pp. 213-227 ◽  
Author(s):  
Wen Cai ◽  
Ryan L Harne
Keyword(s):  
Energy Harvesting ◽  
Nonlinear Vibration ◽  
Power Management ◽  
Partial Information ◽  
Electrical Power ◽  
System Level ◽  
Vibration Energy ◽  
Amplitude Dependence ◽  
Harvesting Systems ◽  
Nonlinear Energy

In recent years, great advances in understanding the opportunities for nonlinear vibration energy harvesting systems have been achieved giving attention to either the structural or electrical subsystems. Yet, a notable disconnect appears in the knowledge on optimal means to integrate nonlinear energy harvesting structures with effective nonlinear rectifying and power management circuits for practical applications. Motivated to fill this knowledge gap, this research employs impedance principles to investigate power optimization strategies for a nonlinear vibration energy harvester interfaced with a bridge rectifier and a buck-boost converter. The frequency and amplitude dependence of the internal impedance of the harvester structure challenges the conventional impedance matching concepts. Instead, a system-level optimization strategy is established and validated through simulations and experiments. Through careful studies, the means to optimize the electrical power with partial information of the electrical load is revealed and verified in comparison to the full analysis. These results suggest that future study and implementation of optimal nonlinear energy harvesting systems may find effective guidance through power flow concepts built on linear theories despite the presence of nonlinearities in structures and circuits.

A parametric analysis of the nonlinear dynamics of bistable vibration-based piezoelectric energy harvesters

2020 ◽  
pp. 1045389X2096318
Author(s):  
Luã Guedes Costa ◽  
Luciana Loureiro da Silva Monteiro ◽  
Pedro Manuel Calas Lopes Pacheco ◽  
Marcelo Amorim Savi
Keyword(s):  
Nonlinear Dynamics ◽  
Energy Harvesting ◽  
Parametric Analysis ◽  
Electromechanical Coupling ◽  
Performance Enhancement ◽  
Piezoelectric Materials ◽  
Electrical Power ◽  
Harmonic Excitation ◽  
Piezoelectric Energy ◽  
Harvesting Systems

Piezoelectric materials exhibit electromechanical coupling properties and have been gained importance over the last few decades due to their broad range of applications. Vibration-based energy harvesting systems have been proposed using the direct piezoelectric effect by converting mechanical into electrical energy. Although the great relevance of these systems, performance enhancement strategies are essential to improve the applicability of these system and have been studied substantially. This work addresses a numerical investigation of the influence of cubic polynomial nonlinearities in energy harvesting systems considering a bistable structure subjected to harmonic excitation. A deep parametric analysis is carried out employing nonlinear dynamics tools. Results show complex dynamical behaviors associated with the trigger of inter-well motion. Electrical power output and efficiency are monitored in order to evaluate the configurations associated with best system performances.

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