Electrical Energy Conversion Research Articles

Beyond Current Frontiers of Electrocatalysis

One of the key reasons why the transition to renewable energy sources is progressing slowly is the low efficiency of processes at electrified interfaces where electricity is converted and stored as chemical energy. The challenge behind low efficiency is sluggish electrochemical conversion reactions. To resolve low efficiency, it is necessary to comprehend the intrinsic reasons behind the unusually complex phenomena of converting electrical energy into chemical energy, and vice versa, chemical energy into electrical energy. An important example is the electrolysis of water, where, after decades of research, it is not clear how to significantly accelerate the processes of hydrogen and oxygen generation. Of critical importance for the control of the water electrolysis mechanism is understanding the origins of the electrocatalytic activity. If we ask a key question from a conceptual point of view, namely: what are the origins of electrocatalytic activity? The answer will be, in most cases, as it was 70 years ago. Namely, the paradigm of electrocatalysis is the Sabatier principle, which suggests optimal ("not too strong, not too weak") binding of intermediates as the main prerequisite for a high reaction rate. Conventional wisdom suggests that confirmation of this should be a linear relationship between the adsorption energy of the intermediate and the activation energy, known as the Brønsted-Evans-Polanyi relation. However, recent results show that lowering the activation energy is not necessarily beneficial for increasing the reaction rate. In this work, some fundamentally important questions about the nature of electrocatalytic activity will be raised. Identifying and analyzing these issues can be an important trigger and driver towards efficient water electrolysis and a more comprehensive understanding of electrocatalysis as a scientific field of key importance for the conversion, storage and utilization of energy from renewable sources.

Research on Water Flow Control Strategy for PEM Electrolyzer Considering the Anode Bubble Effect

At higher current densities, the bubble effect in the anode flow field of the PEM electrolyzer (PEM EL) worsens mass transfer losses and energy consumption. This study employs a moderate increase in the water flow rate to remove accumulated bubbles under fluctuating electrical input, thereby improving PEM EL system efficiency. An enhanced PEM EL equivalent circuit model incorporating bubble over-potential based on the oxygen volume fraction is developed. Considering the energy consumption of auxiliary equipment and the reduction in losses from mitigating the bubble effect, a numerical simulation evaluates the impact of flow rate variations on overall electrolysis energy consumption, leading to a comprehensive energy consumption model for the PEM EL system, incorporating electrical, chemical, and thermal energy conversions. The control objective is to maximize system efficiency by optimizing the water flow rate, with a performance-preset-based controller implemented in MATLAB/Simulink. The simulation results show that the controller can accurately track the target flow rate, and the dynamic regulation time improved by 1.5 s compared to the traditional performance constraint function, better matching the rate of change in electrical energy. Under the water flow control mode, hydrogen production increased by 6.6 L within 130 s of the simulation, available energy increased by 8.32 × 106 J, and the efficiency of the PEM EL system improved by 2.79%.

High-Performance Thermoelectric Composite of Bi2Te3 Nanosheets and Carbon Aerogel for Harvesting of Environmental Electromagnetic Energy.

Intensifying the severity of electromagnetic (EM) pollution in the environment represents a significant threat to human health and results in considerable energy wastage. Here, we provide a strategy for electricity generation from heat generated by electromagnetic wave radiation captured from the surrounding environment that can reduce the level of electromagnetic pollution while alleviating the energy crisis. We prepared a porous, elastomeric, and lightweight Bi2Te3/carbon aerogel (CN@Bi2Te3) by a simple strategy of induced in situ growth of Bi2Te3 nanosheets with three-dimensional (3D) carbon structure, realizing the coupling of electromagnetic wave absorption (EMA) and thermoelectric (TE) properties. With ultra-low thermal conductivity (0.07 W m-1 K-1), the CN@Bi2Te3 composites achieved a minimum reflection loss (RL) of 51.30 dB and an effective absorption bandwidth (EAB) of 6.20 GHz at an optimal thickness of 2.8 mm. Additionally, under a temperature gradient of 80 K, the flexible thermoelectric generator (FTEG) system generates a maximum output power of 42.2 μW. By absorbing 2.45 GHz microwaves to build the temperature difference, the EMA-TE-coupled device achieves an optimal Uoc of 38.4 mV, a short-circuit current of 1.03 mA, and an output power of 9.87 μW upon a radiation time of 50 s. This work establishes a potential pathway for further recycling electromagnetic energy in the environment, which is also promising for the preparation of large-area flexible EM to electrical energy conversion devices.

Micro-Grid Wind Energy Conversion Systems: Conventional and Modern Embedded Technologies - A Review

This study assesses the effectiveness of an electric microgrid wind energy conversion system using both traditional techniques and contemporary embedded systems, such as artificial neural network-based control mechanisms and fuzzy logic control. The text compares and lists the advantages and disadvantages of various types of wind turbines (WTs). Moreover, this control falls into one of two groups: conventional power control or non-traditional power control. On the other side, conventional control describes methods of control such as manually controlling the turbine rotor's rotation speed and using computational analysis. The current work, in contrast, investigates and evaluates contemporary embedded control techniques used in wind energy conversion systems (WECS), including maximum power point tracking, Artificially intelligent control systems, in relation to the control mechanism, provide complete control over the pitch angle, power coefficient, and tip speed ratio for the best possible wind energy extraction. This makes a direct comparison possible. Nonetheless, there are a few drawbacks and difficulties with the two widely utilized contemporary techniques for power quality extractions: artificially intelligent neural networks and their embedded control systems. However, combining contemporary technology with integrated artificial intelligence controllers may be a workable strategy to lessen and even eliminate these difficulties, as well as advantageous for upcoming studies.

Theoretical system of levels of constructing vehicle movement of ground urban electric transport vehicle

Digitalization of the transport industry and the use of artificial intelligence technologies in the automation of control of its main processes determine the need to search for new approaches to the description of electrical complexes and systems of transport purpose, their internal and external system properties. The public ground urban electric transport system is considered as a complex process of conversion, transmission and use of electrical energy and information in the electrical complex of urban electric transport, manifested in the organization of controlled movement of vehicles in specific conditions of production tasks and technology of passenger transportation. Based on the synergetic description of the properties, principles of organization and functioning of a complex production and technical system of urban electric transport, the controlled movement of vehicles has been presented as a multilevel technological process implemented by the electrical complex of urban electric transport. It has been proved that the basis of this process, formed by 5 hierarchically arranged levels, each of which provides a separate specific task of building the movement of vehicles, is the implementation of algorithms of traction electrical equipment. A theoretical system of levels of vehicle motion construction as a multilevel process has been formulated, mathematical models of each level have been identified, and sets of conditions characterizing "external" and "internal" "order parameters" defining hierarchical interlevel interrelations have been determined. The results of the work may be of interest to the developers of control systems of autonomous vehicles and driver assistance systems during the selection and justification of algorithms for the effective control of the electrical complex of traction electrical equipment of urban electric transport.

A High-Speed Train Traction Motor State Prediction Method Based on MIC and Improved SVR

The traction motor realizes the mutual conversion of electrical energy and mechanical energy during the train traction and braking process and is a key component of high-speed trains. The normal operation of the motor is directly related to the safety of high-speed train operation. Changes in temperature signals can reflect faults in the traction motor. By analyzing the internal and external influencing factors of temperature signals, a multi-factor prediction model for traction motors is established based on the maximal information coefficient and improved support vector regression. In this model, highly relevant features selections are performed based on time-delayed sequences and the maximal information coefficient. Using the adaptive particle swarm algorithm to optimize the improved support vector regression algorithm can enhance its accuracy and efficiency. Furthermore, using the K-nearest neighbor algorithm for error prediction will yield more accurate results. By comparing the RMSE, MBE, MAE, and other evaluation metrics of different algorithms under various working conditions, the results show that the prediction method proposed in this paper performs well across different working conditions. This method demonstrates greater adaptability to varying conditions and is more suitable for applications involving high-speed trains.

The use of Oral Exams to Evaluate Experiential Learning Outcomes in a Lab Setting

In the third year of Mechanical and Materials Engineering at Western University, students with limited prior exposure to electricity and electronics are required to take a course in electrical fundamentals. Although outside the traditional boundaries of their engineering discipline, increasingly, electronics has permeated traditional engineering disciplines with conversion of electrical energy to mechanical energy becoming increasingly relevant. To expose students to experiential learning, in the past, students were assigned labs to demonstrate their ability to support experiential learning outcomes. The labs were comprised of a pre-lab component that was to be completed prior to the practical portion of the lab, followed by measurements, analysis and discussion within a lab setting. All components were to be completed by students individually. With the advent of online AI tools, such as ChatGPT and an increase in the number of students in a cohort, the learning value of the labs was diminished, and it no longer was practical to conduct the experiential components of a lab as was performed in the past. New approaches were sought, and this year, landed upon a traditional method of evaluation: the oral examination. This paper outlines the process employed and the associated outcomes of this exercise.

SnSe2 thermal conductivity from optothermal Raman and Stokes/anti-Stokes thermometry

The optothermal Raman method is useful in determining the in-plane thermal conductivity of two-dimensional (2D) materials that are either suspended or supported on a substrate. We compare this method with the Stokes/anti-Stokes scattering thermometry method, which can play a role in both calibration of Raman peak positions as well as extraction of the local phonon temperature. This work demonstrates that the Stokes/anti-Stokes intensity ratio plays an important role in determining the in-plane thermal conductivity of 2D tin diselenide (SnSe2) dry-transferred onto a polished copper (Cu) substrate. The statistically-averaged thermal conductivity of the 108 ± 24 nm-thick SnSe2yielded 5.4 ± 3.5 Wm-1K-1for the optothermal Raman method, and 2.40 ± 0.81 Wm-1K-1for the Stokes/anti-Stokes thermometry method, indicating that the Stokes/anti-Stokes thermometry method to calculate the thermal conductivity of a material can simultaneously increase both precision and accuracy. The uncertainty value was also lowered by a factor of 1.9 from the traditional optothermal Raman method to the Stokes/anti-Stokes thermometry method. The low in-plane thermal conductivity of 2D SnSe2, 1.3-2.9 times lower than bulk, is useful for applications in thermal and electrical energy conversion and thermoelectric devices.

PET-PZT Dielectric Polarization: Electricity Harvested from Photon Energy.

The effect of residual stress or heat on ferroelectrics used to convert photons into electricity was investigated. The data analysis reveals that when the PET-PZT piezoelectric transducer is UV-irradiated with a 405 nm wavelength, it becomes a photon-heat-stress electric energy converter and capacitator. Our objective was to evaluate the PET-PZT photon-heat-stress electric energy conversion performance and the role of the light's wavelength and intensity. Converting waste energy from energy-intensive processes and systems is crucial to reducing the environmental impact and achieving net-zero emissions. To achieve these, innovative materials are needed to efficiently convert ambient energy into electricity through various physical mechanisms, such as the photovoltaic effect, thermoelectricity, piezoelectricity, triboelectricity, and radiofrequency wireless power transfer.

MODEL OF THREE-PHASE ASYNCHRONOUS MOTOR WITH SHORT CIRCUIT ROTOR IN MATLAB PACKAGE

The presented paper examines the specifics of researching the mathematical apparatus of the model of a three-phase АМ with a short-circuited rotor in the matlab package. It has been proven that three-phase АМ with a short-circuited rotor form the basis of a modern electric drive in many branches of industry, agro-industrial complex and transport. A model was developed in the matlab package, which describes the operation of a frequency-regulated electric drive, taking into account theoretical analysis and experimental studies. In the scientific work, the task of combining mathematical modeling and modern computer technologies, which are based on application packages, is fulfilled, which gives the researcher the opportunity to deeply study the processes that occur in all links of the electric drive. With the help of the proposed model, quantitative and qualitative analysis of electromagnetic and electromechanical processes in transient and established modes of operation, research of dynamic mechanical and operational characteristics, analysis of spectral composition and hodographs of spatial vectors of phase voltage and current of an АМ can be carried out. The considered model can be applied not only when powering an asynchronous motor from a three-phase source with a sinusoidal form of voltage, but also when powering it from power semiconductor converters. The scheme of a virtual installation for modeling and researching processes in a three-phase АМ with a short-circuited rotor was developed in the work. The analyzed installation includes the following blocks: three-phase AC voltage source, three-phase AC voltage meter, Selector block, Voltage Measurement block, three-phase АМ under investigation, static torque assignment block, active and reactive power meter, Subsystem block. An analysis of electromagnetic processes in static and electromechanical converters of electrical energy was carried out using the spatial vector method, which has found wide use. With the help of software packages, instantaneous values of symmetrical three-phase variables such as voltage, current, flux linkage were mathematically transformed into one vector.

Fabrication of PVTF Films with High Piezoelectric Properties Through Directional Heat Treatment

Piezoelectric materials can realize the mutual conversion of mechanical energy and electric energy, so they have excellent application prospects in the fields of sensors, energy collectors and biological materials. The poly(vinylidene fluoride) (PVDF)-based polymers have the best piezoelectric properties in the piezoelectric polymer, but they still have a large room for improvement compared with the piezoelectric ceramics. Improving their content of the polar β phase has become a consensus to polish up the piezoelectric performance. Most available studies construct hydrogen bonds or coulomb interactions between the surface of the dopant and molecular chains by doping, which promotes the molecular chains arrangement and thus facilitates the formation of the polar β phase. Recent studies show that the ordered arrangement of molecular chains is also important for piezoelectric properties. At present, the main way to improve the piezoelectric performance of PVDF is through doping or complex heat treatment process. Here, the poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) film was treated by directional heat treatment which used a heating table. Compared with uniform heat treatment like muffle furnace heat treatment, this simple vertical temperature gradient has many advantages for the content of the β phase and the crystallinity of P(VDF-TrFE). The results of the experiment showed that the content of the β phase of films remained at about 88%. When the film thickness was limited to 100 μm and the heat treatment temperature was limited to 200 °C, its crystallinity could reach 75% and the highest piezoelectric coefficient could reach 33.5 ± 0.7 pC/N. P(VDF-TrFE) films based on the experimental methods described above that show great potential for future applications in electronic devices and biomedical applications.

Air drying using Fe3O4-silica gel composite laminates and hollow tubes with magnetic induction heating based adsorbent regeneration

In the context of the chemical industry’s electrification, magnetic induction swing adsorption (MISA) has garnered attention in recent years, as it allows the direct conversion of renewable electrical energy into thermal energy. In this study, MISA was employed as an alternative technology for regenerating gas- and air drying adsorbents. For this purpose, composite adsorbents were synthesized, primarily composed of silica gel (as the adsorbent) and Fe3O4 (as the magnetic susceptor), and structured into either sheets or tubes. The inclusion of Fe3O4 reduced the surface area and mass adsorption capacity, but the hydrophilic character was retained, allowing for sustained water uptake. Additionally, the smaller particle size of silica gel in the composite material, compared to silica gel granules, enhanced the uptake kinetics, leading to faster saturation. Static experiments (without a convective gas flow) indicated that both the electric current and the Fe3O4 content significantly influenced heat generation and, consequently, the regeneration time. With a current of 49.4 A and 20 wt% Fe3O4, the temperature increased by 10 °C after 3600 s, removing 42 % of the adsorbed water. In contrast, at 100.7 A and 40 wt% Fe3O4, the temperature reached 250 °C in just 180 s, resulting in the removal of 92 % of the adsorbed water. The use of an convective flow over the material enhanced the regeneration efficiency to > 97 %. For the first time, a systematic analysis was conducted on the regeneration of integral water-saturated adsorbents using magnetic induction heating.

Boosting Hydrogen Production: Non-Noble Metal Catalysts Optimize Electrodes in Anion Exchange Membrane Water Electrolysis

As the world transitions to renewable energy sources, efficient energy storage is crucial for managing power fluctuations and decarbonize crucial high temperature processes. Achieving grid balance and optimizing renewable energy capacity requires innovative solutions. One promising option is the conversion of electrical energy into hydrogen through Anion Exchange Membrane Water Electrolysis (AEM-WE).AEM-WE combines high hydrogen production rates per electrode area and little production site footprint of Proton Exchange Membrane Water Electrolysis (PEM-WE) with cost-effectiveness of non-noble electrode materials utilized in Alkaline Water Electrolysis (A-WE). To further optimize AEM-WE, it is essential to improve hydrogen production while reducing material costs. This can be achieved through innovative approaches to electrocatalyst and electrode design. However, developing cost-effective catalysts that combine superior efficiency and robustness in aqueous environments, ideally in alkaline conditions, remains a big challenge. In this work, two electrode preparation approaches are investigated. For the anodic OER a corrosion synthesis is been developed to form highly active NiFe-layered double hydroxide (LDH) structures on nickel non-woven porous transport layers (PTL). A highly active cell can be combined with a cathodic HER catalyst, prepared by electrochemical deposition Ni-S on a stainless steel non-woven PTL.In single cell AEM water electrolysis using 1 M KOH-solution utilizing the prepared NiFe-LDH anode and Pt/C cathode, 2.7 A/cm² at 2 V were achieved, surpassing commercially available powder catalysts like NiFe-oxide. Comparative analysis of Ni-S cathode with NiFe-LDH, integrated into a membrane electrode assembly demonstrated superior AEM-WE performance, outperforming the mentioned platinum on carbon catalysts. Electrochemical impedance spectra indicated higher charge transfer activity of Ni-S cathode compared to Pt/C. Importantly, the electrodes prepared in this study exhibited stability under accelerated electrochemical stress tests for 1000 cycles.These approaches provide a simple, inexpensive, scalable and therefore industry-relevant fabrication method with improved active areas and excellent catalytic activity during AEM water electrolysis. Figure 1

Advances in Solid Oxide Electrolysis Cell (SOEC) Technology for Sustainable, Efficient, and Durable Hydrogen Production

The global transition towards sustainable energy sources has significantly heightened interest in efficient hydrogen production technologies. Among these, solid oxide electrolysis cells (SOECs) have emerged as a standout method for their efficient conversion of electrical and thermal energy into hydrogen through water electrolysis. This study presents recent developments in SOEC technology at the Korea Institute of Energy Research, emphasizing crucial innovations in cell and stack designs that enhance both performance and durability under high-temperature electrolysis conditions.Our research demonstrates significant improvements in SOECs, aiming to meet the increasing demand for sustainable and efficient hydrogen production. Innovations include the introduction of cells with thicknesses ranging from 250 to 300 microns and enhanced support porosity of over 40%, transitioning from 8YSZ to 3YSZ for support and subsequently to 9.5YSZ for the electrolyte. These materials achieve higher mechanical strengths and reduced area-specific resistance. These advancements have resulted in a 20-25% reduction in power consumption compared to conventional lower-temperature electrolysis methods such as alkaline, PEM, or AEM, which is crucial for scaling hydrogen production.In stack development, optimized bipolar plate designs and surface treatments have been introduced to ensure efficient steam distribution and effective thermal management. Strategic operational control has maintained stack voltage within optimal ranges (12.8V at 700°C and 14V at 650°C) under a current of 100A, demonstrating robust performance over prolonged periods with minimal degradation—validated by long-term testing showing less than -0.7% degradation per 1000 hours under these specified conditions. Testing and evaluation within the specified range confirmed that there was no observed degradation, considering the reduction in power consumption.These improvements not only showcase our commitment to advancing SOEC technology but also pave the way for its broader application and commercialization. This aligns with global efforts to utilize renewable and nuclear energy resources for environmentally friendly hydrogen production, addressing technical challenges associated with high-temperature electrolysis, and contributing to the low-carbon solution in the global energy transition. Figure 1

An Aqueous Redox Flow Battery Using CO2 as an Active Material

H2 storage system utilizing the interconversion of CO2 and formate, named a chemical hydrogen battery, has been proposed. The system stores H2 via CO2 hydrogenation to produce formic acid (or formate) and releases H2 via formic acid (or formate) dehydrogenation. Beller et al. reported a catalytic system combining lysine with Mn based homogeneous catalysts and pincer ligands to achieve 10 charging-discharging cycles1. In the H2 release step, lysine acted as a base and trapped CO2, generating >99% pure H2. In addition, our research group developed Ir-based homogeneous catalysts that could drive a chemical hydrogen battery2. The Ir-based homogeneous catalyst enabled H2 storage under ambient conditions and produced 1 MPa of H2 in the H2 release step. However, in the chemical hydrogen battery, energy losses are inevitable in the conversion of electrical energy to H2 as chemical energy and H2 to electrical energy, resulting in a loss of more than half of the input electricity.Thus, we considered that the significant energy loss could be overcome by directly storing and generating electrical energy without using H2. In this presentation, we introduce an aqueous redox flow battery in which the anolyte involves a CO2–formate redox pair based on homogeneous Ir catalysts, while the catholyte involves an MnII–MnIII redox pair. The system exhibited a maximum discharge capacity of 10.5 mAh (1.5 AhL-1), capacity decay of 0.2% per cycle, and total turnover number of 2550 after 50 cycles3. In the redox flow battery system, the formation of IrIV and high-valence hydride species, in contrast to the case of the chemical hydrogen battery, worked as active species and was supported by the in situ fluorescence Ir L III-edge XAFS spectroscopic analysis using the newly constructed online setup.

Mechanical regulation strategy for heterogeneous piezoelectric semiconductor thermoelectric structure based on energy conversion

The piezoelectric properties inherent in piezoelectric semiconductors facilitate the manipulation of charge carrier redistribution, enabling the fabrication of electronic devices with adjustable characteristics. However, despite this capability, our understanding of the energy conversion and transfer mechanisms within such devices remains limited. By discarding the assumption of low injection and the approximation of depletion layer, a nonlinear model was developed on piezoelectric semiconductor thermoelectric structure (PS-TES), considering the penetration of hot electrons and regulation of mechanical loadings. The presented model reveals that the input electric energy is partitioned, with a portion being converted into electric potential energy stored (EPES) in non-equilibrium carriers and another portion being the energy dissipation (ED) due to the electrothermal action. Furthermore, from an energy conservation standpoint, a interesting competitive phenomenon between electric potential energy conversion and energy dissipation is obtained. The power of external electric energy input and internal electric energy conversion can be manipulated via mechanical loadings, thereby adjusting the energy conversion process of PS-TES. Finally, we found that the compressive loadings can increase EPES and reduce ED, thereby optimizing the cooling effect at cold end. While tensile loadings can reduce EPES and increase ED, thus causing the PS-TES to locally heat up and produce a heating effect. This study potentially offers a means to switch the performance of TES and provides fresh insights into energy conversion processes within piezoelectric semiconductors.

Improved reactor design enables productivity of microbial electrosynthesis on par with classical biotechnology

Microbial electrosynthesis (MES) converts (renewable) electrical energy into CO2-derived chemicals including fuels. To achieve commercial viability of this process, improvements in production rate, energy efficiency, and product titer are imperative. Employing a compact plate reactor with zero gap anode configuration and NiMo-plated reticulated vitreous carbon cathodes substantially improved electrosynthesis rates of methane and acetic acid. Electromethanogenesis rates exceeded 10 L L–1catholyte d–1 using an undefined mixed culture. Continuous thermophilic MES by Thermoanaerobacter kivui produced acetic acid at a rate of up to 3.5 g L−1catholyte h−1 at a titer of 14 g/L, surpassing continuous gas fermentation without biomass retention and on par with glucose fermentation by T. kivui in chemostats. Coulombic efficiencies reached 80 %–90 % and energy efficiencies up to 30 % for acetate and methane production. The performance of this plate reactor demonstrates that MES can deliver production rates that are competitive with those of established biotechnologies.

MHz High Performance of Soft Magnetic Composite with Ordered Domain Structure for Efficient Conversion of Electrical Energy

AbstractSoft magnetic materials are a core element of power electronics and electrical machines. However, none of the soft magnetic materials is able to exploit the full potential of wide bandgap semiconductors, which operate above MHz frequency for efficient energy conversion in power electronic systems. Here, a high‐performance Fe–Si soft magnetic composites with a 2D ordered domain structure are reported, enabling efficient energy conversion at MHz frequencies. By transforming spherical particles into flakes and arranging them in layers, 2D magnetic domains are created within the composite. This leads to a 90% increase in permeability and a tenfold decrease in loss at 3 MHz compared to composite made with spherical particles. The significantly increased cut‐off frequency indicates that the ordered flaky particles are suitable for MHz applications, unlike the disordered spherical particles. These findings provide an effective approach for fabricating high performance soft magnetic composites from traditional spherical particles and miniaturizing magnetic devices for efficient power electronics operation.

Simulation and Experiments on Optimization of Vortex-Induced Vibration Power Generation System Based on Side-by-Side Double Blunt Bodies

In order to improve the utilization efficiency of converting low-flow current energy into electric energy for Reynolds number 10,000 ≤ Re ≤ 40,000, this paper proposes a vortex-induced vibration power generation system based on a side-by-side double blunt body. In this system, the side-by-side double blunt body structure is used in the current energy capture part to enhance the collection of low-flow current energy; the permanent magnet linear motor is used in the electric energy conversion part to improve the efficiency of electric energy conversion; and a laboratory device is constructed for testing. The effects of the blunt body structure parameters and the center spacing ratio on the energy harvesting performance of the system are qualitatively explained by constructing a simulation model. Compared with the single blunt body energy capture structure, the side-by-side double blunt body structure increases the vibration amplitude by 1.04 times and the lift by 1.14 times at the center spacing S/D = 2.4. Meanwhile, energy harvesting can be realized at a lower flow velocity, increasing the vortex-induced vibration’s energy capture range. Finally, the power generation system was experimentally verified in the laboratory, and the results showed that the vibration amplitude of the double blunt body structure was increased by 1.12 times compared to the single blunt body. The maximum output power of the generator is 10.55 W when the water velocity is 0.7 m/s. The energy conversion efficiency of the power generation system can reach a maximum of 52.93%, which is 12.33% higher than that of a single blunt body structure, which proves that the system has a higher power conversion efficiency than that of a conventional single conversion system.

The Characterization of A Thermoelectric Generator Type TEC1-12706 Hybridized On 50W Polycrystalline PV

The potential of solar energy is very large in generating electrical energy conversion using TEG and PV technology. Therefore, it is important to understand how the technology works. This study aims to characterize the electrical generation of 12 TEG modules type TEC1-12706 hybridized with 2 PV panels. One PV panel is left without a TEG module as a comparison. Meanwhile, on the cold side of the TEG attached to the PV, a heatsink with 3 fins is placed. The left and right fins are air allowed to flow naturally, while the middle fin is flowed with cold water fluid through a 0.01 m diameter water hose with 2 flow rates; 0.02 and 0.05 m / s. The results of the study showed that the fluid flow rate of 0.02 presented a better TEG performance effect than 0.05 m / s at an irradiance of 450 W/m2. Different things are shown by PV solar panels, where the power generation and efficiency are better in TEG at a flow rate of 0.05 m/s compared to 0.02 m/s for the same irradiance. Overall, the performance of PV-TEG is better at a TEG cooling fluid flow rate of 0.05 m/s.