Electric Generator Research Articles

Mapping Capillary Infiltration-Induced Potential in Water-Triggered Electric Generator Using an Electrical Probe Integrated Microscope.

Power generation from water-triggered capillary action in porous structures has recently geared extensive attention, offering the potential for generating electricity from ubiquitous water evaporation. However, conclusively establishing the nature of electrical generation and charge transfer is extremely challenging arising from the complicated aqueous solid-liquid interfacial phenomenon. Here, an electric probe-integrated microscope is developed to on-line monitor the correlation between water capillary action and potential values at any desired position of an active layer. With a probe spatial resolution reaching up to fifty micrometers, the internal factors prevailing over the potential distribution across the whole wet and dry regions are comprehensively identified. Further, the self-powered sensing capabilities of this integrated system are also demonstrated, including real-time monitoring of wind speed, environmental humidity, ionic strength, and inclination angle of generators. The combination of electric potential and chemical color indicator suggests that charge generation is likely correlated with ion-selective transport in the nanoporous channel during the water infiltration process. And unipolar ions (for instance protons) should be the dominant charge-transfer species. The work reveals the fundamental principles regulating charge generation/transfer during the water-triggered electric generation process.

12 Tools for Climate-Smart Decision Making for the Stocker/Feedlot Sector

Abstract There is an increased interest in the use of climate-smart practices and technologies to be more effective in climate change mitigation. These practices include grazing management, pasture management, animal and herd management, animal disease and health, animal breeding, and supplemental feeding during the stocker phase. In the feedlot sector, climate-smart practices range from supply chain challenges including climate smart adaptation by crop producers, cattle type, manure management, health management, and use of growth promoting technologies. There are certainly other technologies not mentioned and are not meant to be marginalized. During the stocker phase, grazing management is highly variable and dependent on climatic conditions and variability, plant species and plant health, water management, soil health, and cattle type. A correct balance among the different land managers, government agencies, and recommendations from university researchers and Extension personnel should optimize these practices. For instance, there is a focus on rotational grazing to increase the efficiency of grazing management. However, in the southwestern U.S. this practice may not be practical given the vast area and landscape used in production. In certain geographical areas, pasture management is becoming increasingly important as decreasing water sources (particularly aquafer levels) are apparent. Some data suggests that now is the time to change from cereal crop production to perennial forages while water is still available to establish the forages. This, in turn, may improve soil health and carbon sequestration. However, as with all mitigation strategies, this may decrease supply of cereal grains available to small feedlot producers, albeit a significant amount of cereals are transported to the cattle feeding sector. Animal breeding programs to improved production, heat tolerance, disease resistance, and improved reproduction is important. As with any production practice, supplementation programs may become necessary under certain situations. It is well known that cattle treated for respiratory disease have poorer performance and carcass characteristics than cattle not treated. Use of growth promoting technologies improve animal performance and decreases total methane produced. No doubt manure production from feeding operations produce methane. Dairy and swine operations can harvest the methane and with use of biogas collectors flare off the methane or produce energy for electric generators, however, this is not practical under feedlot situations; however, application of manure to land may improve soil organic matter. Building resilience in evaluating climate-smart practices will satisfy multiple objectives including impacting food security without many constraints to adoption.

Efficiency Improvement of Energy Harvesting Device Using Light Pressure Through Plasmon Coupling at the Interface Between Grained Ag Layer and Au Nanoparticles

AbstractElectricity generation using the piezoelectric effect is an important energy harvesting method. In this study, a solar radiation pressure‐driven crater‐shaped light pressure electric generator (LPEG) device with a Pb(Zr0.52, Ti0.48)O3 (PZT) piezoelectric layer and grained Ag layer is fabricated on GaAs(100) wafer. The electrical output of the device is improved by adsorbing Au nanoparticles (AuNPs) on the Ag layer with the surface of closely connected Ag nanoparticles (AgNPs). By controlling the size and concentration of the AuNPs, a maximum power density of 867.5 µW cm−2 is obtained under a solar simulator (AM 1.5G), which represents a 151.7% improvement over the case without AuNP adsorption. The results of Raman spectra, finite‐difference time‐domain (FDTD) simulations, and COMSOL Multiphysics demonstrate that the newly formed hotspots between AgNPs─AuNPs and AuNPs─AuNPs enhance the electric field of the incident light significantly and extend the region where the electric field is maximally amplified to 600–800 nm, resulting in increased solar radiation pressure on the PZT piezoelectric layer.

Numerical and experimental investigation of a combustor-coupled free-piston Stirling electric generator

In this paper, a novel gas combustor with multiple nozzles is proposed to couple with a free-piston Stirling electric generator (FPSG) for distributed power application. Due to the simple layout of the combustor and intrinsic external combustion of the FPSG, the system is highly adaptive to gas fuels, such as butane, natural gas and liquefied petroleum (LPG). In order to unravel the heat transfer characteristics of external combustion with internal oscillating flow, a rigorous numerical simulation was conducted, and a series of experiments were carried out to verify the calculations. Initially, an in-depth analysis was performed in terms of the flow field, temperature distribution and heat flux density within the combustor. The effects of the combustor inlet flow rate, nozzle structure, and preheating temperature on the flow heat transfer characteristics were explored. Numerical calculations reveal that, at a fuel flow rate of 0.55 Nm3/h and an air-fuel ratio of 24, the high-temperature heat exchanger (HHX) absorbs 6.41 kW heating power, with convective heat occupying approximately 73.5 %. Moreover, the simulations unveil the significant influence of optimizing the air–fuel ratio, nozzle structure, and preheating temperature on enhancing the overall heat transfer performance and achieving fuel and air consumption reductions. Subsequently, we meticulously conducted experimental investigations to comprehensively evaluate the performance of the novel combustor-coupled FPSG. The experimental results demonstrate that, under a fuel flow rate of 0.55 Nm3/h, the system achieves an output electric power of 1531 W, corresponding to a net thermal-to-electric efficiency and fuel-to-electric efficiency of 30.9 % and 9.6 %, respectively.

Modified Efficient Energy Conversion System Based on PMSG with Magnetic Flux Modulation

The article presents the solution of a power rectifier system dedicated to cooperating with an electric generator based on a special synchronous generator, which can be used in wind or water energy systems. In this generator, a pair of three-phase windings in a stator is utilized. One of the windings is connected in a star, and the second one is connected in a delta configuration. Two six-pulse uncontrolled (diode) rectifiers are included at the outputs of the windings. The rectifiers are coupled by a pulse transformer. The primary windings of this transformer are supplied by a power-electronics current source called a current modulator. With the help of this current modulator, the quasi-sinusoidal magnetomotive force (mmf) in the stator of the machine can be obtained. Additionally, to improve the efficiency of the described system, the low-power transistor rectifier, which is connected to the DC bus of the current modulator, has been used. With the help of this converter, it is possible to control and stabilize the voltage level in a DC circuit. It works, in this case, in inverter mode. The principle of working and elaborated control methods of the current modulator and the additional rectifier are presented. Selected results of simulation and experimental tests are also presented.

Distributed Predictive Secondary Control With Soft Constraints for Optimal Dispatch in Hybrid AC/DC Microgrids

Hybrid AC/DC microgrids (H-MGs) are a prominent solution for integrating distributed generation and modern AC and DC loads. However, controlling these systems is challenging as multiple electrical variables need to be controlled and coordinated. To provide flexibility to the control system, these variables can be regulated to specific values or within secure bands. This paper proposes a set of distributed model predictive control schemes for the secondary control level to control certain variables to specific values and other variables within secure pre-defined bands into H-MGs. Specifically, optimal dispatch of active and reactive power is achieved while frequency and voltages are regulated within secure bands in H-MGs. Dynamic models of AC generators, DC generators and interlinking converters along with their novel multi-objective cost functions are developed in constrained distributed predictive optimisation problems to simultaneously achieve the aforementioned objectives via information sharing. Extensive simulation work validates the performance of this proposal.

The discharge characteristics and benzene degradation performance of a three-electrode DBD reactor powered by dual AC power generators

A three-electrode hybrid volume/surface dielectric barrier discharge (V-SDBD) configuration with two plane electrodes and six grounded strips electrode was designed for enhancing the generation of discharge plasma to degrade gaseous benzene. Two plane electrodes were separately powered by a 5 kHz AC generator and a 50 Hz AC generator, respectively. Compared with the typical two-electrode volume DBD (VDBD) reactor excited by 50 Hz AC generator, the hybrid V-SDBD reactor has lower onset discharge voltage and better discharge homogeneity, and the benzene degradation efficiency of V-SDBD was 1.12 times higher than that of VDBD at a similar energy efficiency. Moreover, an increase in the voltage on HVE-II promoted benzene degradation, but decreased the energy efficiency of benzene degradation.

High-precision and flexible magnetoelectric sensor operated at 25–330 °C

It is a big challenge to in situ monitor the health status of high-temperature magnetic equipment such as electric motors and generators since it is difficult to achieve a high-temperature magnetoelectric sensor. Here, the Pb(Zr0.52Ti0.48)O3 film with a ferroelectric Curie temperature of 400 °C and the Metglas alloy slice with a magnetic Curie temperature of 430 °C were combined by using a high-temperature inorganic glue to achieve a high-temperature magnetoelectric sensor. The magnetoelectric coefficient αE of the flexible sensor is as high as 104 V/(cm Oe) at 25 °C, 63.6 V/(cm Oe) at 200 °C, and 39.7 V/(cm Oe) at 330 °C. Besides, the magnetic sensor has a detection accuracy of ∼0.3 nT at 25–330 °C. Most importantly, the high-temperature sensor is flexible, high precision, low cost, light weight, and low power consumption simultaneously.

Amplifying electrical outputs of polyaniline-based Schottky DC generators through single polarity charge injection

Schottky direct-current (DC) generators have gained attention for their ability to produce DC output directly without rectification. However, a major challenge is their limited voltage output, often below 1 V, and difficulty in simultaneously increasing both voltage and current outputs. This study develops a new design concept to improve the voltage and current outputs of a conducting polymer/metal Schottky DC generator by injecting a single type of charges from the Schottky unit's exterior to either its semiconductor or metal components. By utilizing a polyaniline-coated fabric and a metal Al plate to create a Schottky DC generator, as well as a single-mode triboelectric device such as PTFE film/metal Al, PTFE film/PA6 nanofiber membrane, or PA6-Ni/Cu plate as the external charge supplier, we demonstrate that injecting positive tribo charges to the Schottky Al electrode or negative charges to the polyaniline results in a significant increase in both the voltage and current outputs of the Schottky generator. The resultant Schottky unit showcased an exceptional peak open circuit voltage increasing to 4.88 ± 0.20 V, and an equally impressive peak short circuit current output peaking at 154.97 ± 5.20 μA (6.20 ± 0.21 μA/cm2). Remarkably, this configuration delivered an outstanding power density of up to 7.37 μW/cm2. These output metrics surpass those of standalone PANI/Al Schottky DC generator counterparts (1.09 ± 0.03 V, 67.32 ± 6.52 μA, and 0.66 μW/cm²), and also surpass most other Schottky DC generators previously reported. Incorporating nano Coulombs of charge into the Schottky generator resulted in an impressive micro Coulombs of charge migration within the Schottky device, achieving a remarkable fourfold amplification of voltage outputs and twofold amplification of current outputs, all while preserving the inherent DC output characteristics intrinsic to Schottky generators. Moreover, we have observed that the amount external tribo charges have a direct relationship with the voltage and current output increases of the Schottky DC generators. These phenomena were consistent, whether introducing positive charges to the Al layer of the Schottky unit or infusing negative charges into the polyaniline layer. Furthermore, alternative triboelectric devices connected to the Schottky generators yielded similar outcomes, thereby corroborating the robustness of our approach. This novel approach shows promise in enhancing power generation efficiency in Schottky DC generators and has potential applications in various fields requiring efficient and direct DC power generation.

A Comparison of Power Take-Off Architectures for Wave-Powered Reverse Osmosis Desalination of Seawater with Co-Production of Electricity

Several power take-off (PTO) architectures for wave-powered reverse osmosis (RO) desalination of seawater are introduced and compared based on the annual average freshwater production and the size of the components, which strongly relate to the costs of the system. The set of architectures compared includes a novel series-type PTO architecture not previously considered. These seawater hydraulic PTO architectures are composed of a WEC-driven pump, an RO module, an intake charge pump driven by an electric motor, and a hydraulic motor driving an electric generator for electric power production. This study is performed using an efficient two-way coupled steady-state model for the average performance of the system in a given sea state, including freshwater permeate production, electric power production, and electric power consumption. A multi-objective design problem is formulated for the purposes of this comparative study, with the objectives of maximizing annual freshwater production, minimizing the displacement of the WEC-driven pump, and minimizing the installed RO membrane area. This establishes a framework for comparison in the absence of a mature techno-economic model. The requirement that the system produces enough electric power to meet its consumption is applied as a constraint on the operation of the system. The oscillating wave surge converter Oyster 1 is assumed as the WEC. Weights on performance of the system in a given sea state are based on historical data from Humboldt Bay, CA. This study finds that (1) architectures in a series configuration allow for a reduction in the WEC-driven pump size of 59–92% compared to prior work, (2) varying the displacement of the WEC-driven pump between sea conditions does not provide any significant advantage in performance, and (3) varying the active RO membrane area between sea condition offers improvements between 7% and 41% in each design objective.

Experimental study of Undershot Type Water Wheels as Picohydro Power Generators in Irrigation Channels

The need for electrical in rural areas are continues to increase. Meanwhile, the procurement of power plants are limited and experiences many obstacles. The aim of this testing study a hydroelectric power plant in a tourism area is to provide the electricity appropriate that location by utilizing the potential of natural resources. The undershot type water wheel is used as a driving force to drive the electric generator. The resources used come from the flow of irrigation canal which is usually used to irrigate rice fields and the others needs of farmer communities. Measurements of rotation speed, electrical voltage and power produced were carried out within seven days. It is estimated that the generator can produce 75 Watts. The electricity can be utilized for lighting the entrance of tourism areas, food stalls and a residence house. To increase power production found modifications to the irrigation canals need to be considered.

Cathodic protection of a buried pipeline by solar energy

Cathodic protection is employed intensively on the steel drains in oil and gas industry. It is a technique of prevention against the corrosion which transforms the structure into a cathode of a corrosion cell; Two types of cathodic protection systems are usually applied: The galvanic protection systems use the galvanic anodes, also called the sacrificial anodes, which are electrochemically more electronegative than the structure to be protected, the other system is by imposed current, powered by electrical generator with D.C. output towards the structure to be protected. The object of this study is to design a cathodic protection system by impressed current supplied with solar energy panels applied to a pipeline.

DFIG versus PMSG for marine current turbine applications

Emerging technologies for marine current turbine are mainly relevant to works that have been carried out on wind turbines and ship propellers. It is then obvious that many electric generator topologies could be used for marine current turbines. As in the wind turbine context, doubly-fed induction generators and permanent magnet generators seems to be attractive solutions to be used to harness the tidal current energy. In this paper, a comparative study between these two generators type is presented and fully analyzed in terms of generated power, maintenance and operation constraints. This comparison is done for the Raz de Sein site (Brittany, France) using a multi physics modeling simulation tool. This tool integrates, in a modular environment, the resource model, the turbine hydrodynamic model and the generators models.

Increasing the Effectiveness of Electricity-Generating Floors Through the Mechanical Energy of DC Generators

The increasing electricity consumption of the Indonesian population requires renewable energy as an alternative to electricity generation supplies. Renewable energy can be formed through mechanical energy in its simplest form, namely in the form of a footrest. Generally, energy-harvesting floors that utilise human footsteps are designed with piezoelectric sensors. This sensor is responsible for converting mechanical energy into electrical energy. However, the power generated from piezoelectrics is only around 0.041 μW to 240.59 μW. So, in this study, an alternative design for a footstep floor is proposed capable of harvesting electrical energy using a DC generator. The proposed platform consists of a platform design that utilises the translational motion of the gears on the gear rack and is assisted by four springs surrounding the sides of the iron plate. Apart from that, the platform has a power management and storage system. Unlike controllers in general, solar charger controllers are used for charging (voltage and current in the accumulator) and flowing current to the load (lights). The subjects used in this floor test ranged from 20-100 kg. Compared to floors that use piezoelectrics, the results are that floors with DC generators experience an increase in power of around 0.62%. Hence, DC generators are more effective in harvesting electrical energy.

Proposing of a novel PV/T module in series with a ST+TE module to pursue a round-the-clock continuous energy output

As is well known, traditional solar systems can only work under conditions of solar radiation, as solar energy is the sole energy source for photovoltaic generation and heat recovery. Few studies have focused on their continuous operation throughout the day and this research gap needs to be filled. Consequently, to pursue a round-the-clock electrical power generator, in this study, a two-stage system is constructed, consisting of the first-stage photovoltaic/thermal module and the second-stage solar thermal collector with thermoelectric generators in series. Thermoelectric generators ensure that the system runs normally by day, while also utilizing the heated fluid to achieve uninterrupted energy output at night. A numerical model of the system is developed to analyze the performance changes under continuous running. From the results, the second-stage module improves the daytime heat gain, effectively boosting the electrical contribution of thermoelectric generators, whether during the day or night. At the maximum input energy, photovoltaic cells generate the greatest power of 118.37 W with an average efficiency of 14.56%. The average efficiencies of thermoelectric generators in the daytime and nighttime are 0.97% and 0.53%, enhancing the total electrical output. Additionally, the comparative analysis is performed under different parameters, as well as an economic analysis.

A Theoretical Approach in the Design of Single Frame 28 V DC and 270 V DC Dual Voltage Generator

Armored Fighting Vehicles (AFVs) generally operate with a 28 V DC electrical system. However, the demand for electrical power in AFVs has exceeded the capabilities of the existing 28V system. The additional load growth necessitates larger wire sizes, which adds extra weight and cost to the vehicle. Introducing a dual-bus architecture (28 V DC and 270 V DC) can lead to the efficient operation of the electrical system while meeting future demand. This paper presents the design of a Brushless Direct Current (BLDC) Dual Voltage Generator (DVG), which simultaneously outputs two voltages (28 V DC & 270 V DC) from a single frame across a wide operational speed range. The design process includes a detailed description of the individual stages, accompanied by analytical parameters and software-generated results. The modeling and analysis of the generator were carried out using Motorsolve design software. The obtained results are presented and thoroughly discussed in this paper.

Experimental Analysis of Fluke 345 Measurement Instrument Laboratory: Unloaded and Loaded Engines Case Studies

This scientific initiative project was carried out using the resources available in the laboratories of the Federal Universityof Tocantins (UFT), focusing on the Fluke 345 measuring equipment. The experiment presented in this paper involved two differentapproaches: one with an unloaded engine and another with a load consisting of a DC generator, both powered by a 60-volt supply. TheFluke 345 measures the voltage RMS, current RMS, and power factors and plots them along with the harmonic analyzes. The experimentshowed that no harmonics were detected at no load, while harmonics occurred under load. The data collected validates the theoreticalconcepts through practical application. This study provides valuable insights for power engineering, especially regarding the performanceof the devices under different conditions.

A self-stabilizing point absorber wave energy converter with a top-shaped buoy and non-linear power take-off for oceanographic applications

Point absorber wave energy converters (PA-WECs) are considered an independent renewable energy resource in oceanographic research to study wave climate data, ocean navigation and maritime security. Their performance enhancement through optimally designed floats and power take-off (PTO) is a crucial challenge. The proposed study investigates the combined PA-WEC model, including (i) the hydrodynamic of the optimally designed top-shaped buoy, (ii) non-linear characteristics of power take-off and (iii) self-stability of PA-WEC under the real-time wave climate of XiaoMaiDao wave station, Shandong, China. The proposed mechanical power take-off comprises a double-sided rack with gear transmission and three-phase DC generators. The components of the power take-off are symmetrically oriented on both sides of the rack to make it statically and dynamically balanced for the self-stability of the PA-WEC. The floating buoy absorbs kinetic energy from waves relative to a fixed point and transfers it to the PTO system. The PTO module alters the forward and reverted strokes of heaving motion into uni-directional rotations on the output shaft, employing a mechanical gearing mechanism with one-way bearings. Subsequently, supercapacitors store the rectified electrical energy in the power conversion and storage modules. The mechanical power take-off was initially modeled in MATLAB/Simscape and verified through experimental investigations using mechanical testing and sensing machine. Secondly, the hydrodynamics of the floating buoy was studied using frequency- and time-domain simulations in ANSYS AQWA. Thirdly, the wave tank tests were performed on a 1:25 scaled buoy in a wave tank, and the test results were validated against the time-domain simulations. Finally, the combined effects of power take-off and buoy were studied on the prototype scale, and it is concluded that at 1m significant wave height, the power take-off system integrated with the Cyl-AS buoy can generate 247.76W (RMS) with PTO efficiency of ηpto_rms = 76.37% at PA-WEC efficiency of ηwec_rms = 12.10%. Installing the proposed point absorber wave energy converter system along the offshore platforms can promote the UN-SDG-2030 Agenda, specifically the 7 and 14 goals, by supplying electricity for oceanographic applications.

Detection and characterization of mono- and bimetallic nanoparticles produced by electrical discharge plasma generators using laser-induced breakdown spectroscopy

This work investigates the performance of laser induced breakdown spectroscopy (LIBS) for the detection and characterization of nanoparticles generated by spark discharge generators (SDG) and arc discharge generators (ADG). LIBS nanoaerosol analysis was carried out according to both on-line (in a gas stream) and off-line (after collection on a filter) methodologies for monometallic (Cu and Au) and bimetallic (AgCo, SnCu, AgAu) nanoparticles generated by ADG and SDG. It was shown that LIBS is not only capable of detecting the presence of nanoparticles in real time, but LIBS spectra can also be used to provide qualitative and quantitative compositional information, as well as estimates for the particle number concentration. This analytical capability, combined with the compact and robust character of LIBS instrumentation, can be put to use for the real-time monitoring of industrial gas-phase nanoparticle synthesis or environmental or workplace exposure to nanoparticles.

Power Generation from Utilizing Thermal Energy of Hazardous Waste Incinerators

A large amount of thermal energy is generated from burning hazardous chemical wastes, and the temperature of the flue gases in hazardous waste incinerators reaches up to (1200 °C). The flue gases are cooled to (40°C) and are treated before emission. This thermal energy can be utilized to produce electrical power by designing a system suitable for dangerous flue gases in the future depending on the results of much research about using a proto-type small steam power plant that uses safe fuel to study and develop the electricity generation process with water tube boiler which is manufactured experimentally with theoretical development for some of its parts which are inefficient in experimental work. The studied system generates theoretically (120 kg steam /h at 8 bars) with dry wood as fuel and preheating for the air of combustion and feed water and a diesel engine of (8 hp) four-stroke with single piston converted to steam engine coupled with the electrical generator of (3 kVA). The results are compared with practical values valid in the literature about small power plants of steam capacity (0.1-1) ton/h and operating pressure up to 10 bars. Experimentally, the generated electrical power is little and sufficient to operate a small fan and lump. The current converted steam engine is better than a conventional steam engine in auto lubrication with some operational problems. The boiler efficiency is 63.28%.