Electrical Characteristics Of Generator Research Articles

Numerical Methods to Evaluate Hyperelastic Transducers: Hexagonal Distributed Embedded Energy Converters

Hexagonal distributed embedded energy converters, also known as hexDEECs, are centimeter-scale energy transducers that leverage variable capacitance to generate electricity when their hyperelastic structure is dynamically deformed. To better understand, characterize, and optimize hexDEEC designs, a series of numerical methods and techniques were developed to model the hyperelastic mechanics of hexDEECs, electrostatic properties, and electricity generation characteristics. The numerical methods developed for the hyperelastic structural analysis were corroborated by empirical results from another study, and the models and equations for capacitance, electrostatic forces, and electrical potential energy were derived from fundamental electrostatic equations. These methods and techniques were implemented within the STAR-CCM+ multiphysics software Version 2020.3 (15.06.008) environment. Results from this analysis revealed methodologies and techniques necessary to model the energy converters, which will enable future exploration and optimization of more specific designs and corresponding applications.

Superhigh charge density and direct-current output in triboelectric nanogenerators via peak shifting modified charge pumping

Due to the great potentials in self-powered sensors and micro-nano power sources, triboelectric nanogenerator (TENG) has attracted numerous attentions. However, enhancing charge density and realizing direct-current (DC) are long-term significant issues for TENGs. In this work, we investigated a DC TENG with outstanding electricity generation characteristics based on quasi- synchronous double-stage self-charge pumping. The TENG works in a contact-separation mode with a four-layered parallel structure. The TENG possesses a high open-circuit voltage of 2300 V, a high short-circuit current of 3 mA, a high power of 150 mW and a superhigh transferred charge of 20 μC at 4 Hz, which are significantly enhanced from those in single-stage pumping and non pumped counterpart TENGs. The property-improving mechanism lies in that through the unidirectional self-charge pump with a slight time difference among TENGs, negative halves are moved to the adjacent positive halves, leads to the widening, higher and DC outputs at the final terminal, which employs the Plancherel theorem for peak shifting in framework of energy conservation law. The TENG can power light emitting diodes, electronic devices and an electrophoretic deposition of pigment coatings. This work provides a method for developing high-performance DC TENGs with superhigh transferred charge for various applications.

Effect of acoustic radiation from circular plate installed with piezoelectric element on electricity generation performance

This study examined the electricity generation performance of an energy-harvesting system, in which a circular plate with a piezoelectric element was excited by a harmonic point force. The theoretical electricity generation efficiency, which does not involve acoustic radiation from the plate, is greater than the experimental efficiency in such a power generation system, and the discrepancy between the theoretical and experimental efficiencies increases with the plate thickness. A sound field is formed in the atmosphere surrounding the plate, whose vibration compresses the medium on the plate surface and causes a reaction force to the plate. In such a system, it is difficult to completely avoid the effect of acoustic radiation; therefore, the abovementioned effect must be examined to estimate the electricity generation characteristics of the system. The generation characteristics are estimated not only by the radiation resistance that is involved in the acoustic radiation, but also by the reaction force caused by the sound pressure on the plate. Consequently, the power reduced by the reflection of the reaction force and sound pressure decreased because of the increasing flexural rigidity of the plate when the plate thickness increased while the radius remained constant. However, because the radiation resistance increases with the plate thickness, the acoustic radiation energy, except for the work exerted by the sound pressure, is emitted to the atmosphere. To utilise such acoustic radiation energy, a new electricity generation system comprising a steel cylinder with two plates at both ends was used, where a sound field was formed within the cylinder. The system performance was estimated in terms of the electricity generation efficiency by comparing it with that of the abovementioned plate system. As a result, although the thin plate was preferable to increase the efficiency because of the weakened acoustic radiation, the thick plate was useful to harvest vibration energy, which was unused normally, because of enabling to apply mechanical–acoustic coupling between the plate vibrations and the internal sound field.

Study on the Electricity Generation Characteristics of Microbial Fuel Cell with Different Substrates

We use anhydrous sodium acetate, glucose, lactose and Colocasia antiquorum Schott as anode substrate to study the periodic curve of battery voltage and stable output voltage of different substrates, The results showed that the four kinds of microbial fuel cells with sodium acetate, glucose, lactose and pretreated Colocasia antiquorum Schott as anode substrate had the following power generation periods: 23.98 d, 20.15 d, 18.84 d and 23.52 d, respectively, and the stable voltage at the two ends of the resistance of microbial fuel cells with four different anode substrates are 0.77 V, 0.75 V, 0.65 V and 0.70 V respectively. We found at the same carbon source concentration, MFC with sodium acetate as the substrate has the best electricity production characteristics. When the pretreated Colocasia antiquorum Schott is used as anode substrate, the time for cell voltage to rise from initial value to stable value is the shortest, and as a carbon source, it can also play a dominant role in the process of electric energy collection and utilization.

A time-varying carbon intensity approach for demand-side management strategies with respect to CO2 emission reduction in the electricity grid

The main aim of this study was to determine electricity utilisation based on the hourly distribution of CO2 emissions. Turkey was chosen for this case study because of the CO2 intensive characteristics of electricity generation. This study aims to be a pioneer in the spread of a time-varying carbon intensity approach for the calculation of carbon foot prints. Electricity generation-based hourly emissions are calculated by utilising actual data. It varies from 418.6 g CO2/kWh to 824.6 g CO2/kWh, or 597.8 g CO2/kWh on average. According to hourly basis analyses, the highest CO2 intensity of electricity generation occurs between 06:00 and 07:00. The highest CO2 intensity of electricity generation occurs on a Sunday despite this being the time of lowest electricity demand. An annual total of 162.84 metric tons of CO2 is released into the atmosphere as a result of electricity generation. Electricity generation-based CO2 emission per capita is calculated as 2.04 ton CO2.

Experimentally and Numerically Analyzed Piezoelectric Characteristics of PZT Ceramics

The electric generation characteristics of the PZT piezoelectric ceramics were examined experimentally and numerically. In this case, cyclic bending loading was applied to the PZT ceramics: bulk and thin-film membrane. Electric voltage increased with increasing the strain value. There was a sharp initial increase in positive voltage for the PZT ceramics as bending load was applied. Following this initial increase stage, a rapid fall to zero occurred. The reduction rate of the positive voltage was changed depending on the rigidly of the PZT ceramic: the higher the reduction rate, the higher the rigid of the ceramic. The electrical voltage from the circular membrane PZT ceramic during cyclic loading showed the higher level compared to that for the bulk one, in which the flexibility of the PZT ceramic was significant factor to obtain the high electric voltage. The variation of the electric voltages was estimated numerically, which was relatively in good agreement with the experimental one.

Electroactive polymers for ocean kinetic energy harvesting: literature review and research needs

The recent issue of serious global warming has stimulated research on the development of de-carbonized energy harvesting technologies. The ocean has the most valuable natural resources which have resulted in the construction of a wide variety of offshore plants all over the world. Because nearly all offshore plants are stand-alone plants that do not transmit electricity, they must have their own power generators. This paper aims to provide a source of information on ocean kinetic energy harvesting with electroactive polymers from the natural oscillations of ocean waves and currents. Electroactive polymers play an important role due to having electricity generation characteristics that correspond to mechanical stimuli. Among them, dielectric elastomers and piezoelectric materials have shown considerable promise for harvesting energy from environmental sources, such as ocean waves and currents. Ionic polymer metal composites, which are known as ionic electroactive polymers, are emerging materials in energy harvesting applications because of their favorable electromechanical characteristics and their highly compliant nature. Moreover, their intimacy with water enables them to be used in a water environment, which is suitable for ocean energy harvesting. Electroactive harvesting for the ocean kinetic energy has the potential to coexist with marine environments.

Influence of loading conditions on electric generation characteristics of PZT ceramics

Influence of loading conditions on electric generation characteristics of PZT ceramics

Efficient energy management for a grid‐tied residential microgrid

In this study, an effective energy management system (EMS) for application in integrated building and microgrid system is introduced and implemented as a multi-objective optimisation problem. The proposed architecture covers different key modelling aspects such as distributed heat and electricity generation characteristics, heat transfer and thermal dynamics of sustainable residential buildings and load scheduling potentials of household appliances with associated constraints. Through various simulation studies under different working scenarios with real data, different system constraints and user's objectives, the effectiveness and applicability of the proposed model are studied and validated compared with the existing residential EMSs. The simulation results demonstrate that the proposed EMS has the capability not only to conserve energy in sustainable homes and microgrid system and to reduce energy consumption costs accordingly, but also to satisfy user's comfort level through optimal scheduling and operation management of both demand and supply sides.

Electricity Generation Characteristics of Energy-Harvesting System with Piezoelectric Element Using Mechanical-Acoustic Coupling

This paper describes the electricity generation characteristics of a new energy-harvesting system with piezoelectric elements. The proposed system is composed of a rigid cylinder and thin plates at both ends. The piezoelectric elements are installed at the centers of both plates, and one side of each plate is subjected to a harmonic point force. In this system, vibration energy is converted into electrical energy via electromechanical coupling between the plate vibration and piezoelectric effect. In addition, the plate vibration excited by the point force induces a self-sustained vibration at the other plate via mechanical-acoustic coupling between the plate vibrations and an internal sound field into the cylindrical enclosure. Therefore, the electricity generation characteristics should be considered as an electromechanical-acoustic coupling problem. The characteristics are estimated theoretically and experimentally from the electric power in the electricity generation, the mechanical power supplied to the plate, and the electricity generation efficiency that is derived from the ratio of both power. In particular, the electricity generation efficiency is one of the most appropriate factors to evaluate a performance of electricity generation systems. Thus, the effect of mechanical-acoustic coupling is principally evaluated by examining the electricity generation efficiency.

Characteristics of electricity generation with intermittent sources depending on the time resolution of the input data

Data on the electricity supply with intermittent renewable sources are made public by the Transmission System Operators (TSO) and other sources. Data are typically provided in 1h increments. In this paper, we analyse wind and photo-voltaic data from the Czech Republic. The analysis concentrates on major characteristics of a supply situation where the annual demand is formally met by scaled-up wind and photovoltaic power. The original data are supplied in 1min increments and successively averaged up to 1h time resolution. This paper focuses on the dependence of the major supply characteristics on the time resolution of the available electricity data.

A study of the electric power generation properties of a lead zirconate titanate piezoelectric ceramic

Electric power generation characteristics of lead zirconate titanate (PZT) piezoelectric ceramic have been investigated experimentally and numerically. A thin PZT ceramic plate attached to a thin brass plate was used to examine the electric voltage generated during cyclic loading. On increasing the number of PZT ceramic plates combined together in the longitudinal direction, the electric voltage increases with the highest electric voltage being obtained for four PZT ceramic plates; and the maximum electric voltage becomes almost constant even if the number of PZT ceramic plates combined together increases more than four. This is attributed to the low strain level and the mixed strain (compressive and tensile strain). The effect of strain characteristic on the electric voltage value was analyzed numerically using our strain definition, and a clear correlation between the extent of compressive strain and generated electric voltage is clarified. A different electric generation characteristic was further observed depending on the stress conditions: generation of positive and negative electric voltage occurs when the PZT ceramic is subjected to mainly compressive and tensile stress, respectively.

Precise analysis of compressive strain effects on electric power generation properties of a lead zirconate titanate piezoelectric ceramic

Electric power generation characteristics of lead zirconate titanate (PZT) piezoelectric ceramic have been examined during cyclic loading with different compressive strain value. A thin PZT ceramic plate attached to a thin brass plate was used. With an increasing compressive strain value in the PZT ceramic plate, the electric voltage increased, and the highest electric voltage was obtained for the sample with the high strain level (0.4%). The electric voltage decreased for the sample with more than 0.45% strain because of the failure in the PZT ceramic. The electric voltage was different depending on the strain condition, where the higher strain and the wider strain range (Δe) made the high electric voltage. Moreover, the electric voltage was attributed to the strain rate, where the higher strain rate made higher electric voltage due to high kinetic energy. The electric generation characteristics could be estimated with an operation of the strain value and strain ratio (emin/emax) especially for the sample loaded cyclically under the slow loading speed. This was affected by the linear correlation between the electric voltage and the strain value. Based upon the experimental work, suitable loading condition to make high electric voltage could be proposed.

Effects of Substrate on the Electricity Generation Characteristics of Microbial Fuel Cell

Effects of Substrate on the Electricity Generation Characteristics of Microbial Fuel Cell

Effect of electricity on microbial community of microbial fuel cell simultaneously treating sulfide and nitrate

The effect of electric current on microbial community is explored in Microbial Fuel Cells (MFCs) simultaneously treating sulfide and nitrate. The MFCs are operated under four different conditions which exhibited different characteristics of electricity generation. In batch mode, MFCs generate intermittently high current pulses in the beginning, and the current density is instable subsequently, while the current density of MFCs in continuous mode is relatively stable. All operational parameters show good capacity for substrate removal, and nitrogen and sulfate were the main reaction products. Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) analysis is employed to obtain profiles of the bacterial communities present in inoculum and suspension of four MFCs. Based on the community diversity indices and Spearman correlation analyses, significant correlation exists between Richness of the community of anode chamber and the electricity generated, while no strong correlation is evident between other indexes (Shannon index, Simpson index and Equitability index) and the electricity. Additionally, the results of Principal Component Analysis (PCA) suggest that MFCs suffering from current shock have similar suspension communities, while the others have diverse microbial communities.

Electricity generation and COD removal of microbial fuel cells (MFCs) operated with alkaline substrates

The characteristics of electricity generation and COD removal of dual-chamber microbial fuel cells (MFCs) operated with alkaline substrates were studied. Substrates with constant pH of either 7 or 9 as well as varying pH in a cycle of 7-8-9-8-7 were used. MFCs operated with these substrates were denoted as MFC-pH7, MFC-pH9 and MFC-pHV, respectively. The experimental results indicate that the MFC-pHV can generate the highest performance of 2554 ± 159 mW/m2. Cyclic voltammetry (CV), active biomass and electrochemical impedance spectroscopy (EIS) measurements were conducted and these results suggested that the MFC-pHV had the highest electrochemical activity per unit biomass and the lowest internal resistance, which together contributed to the improved power output of the MFC-pHV. In addition, compared with the other two MFCs operated at fixed pH values, the COD removal efficiency of the MFC-pHV was improved due to the stronger adaptation to the varying pH-environment.

Treatment of sewage and synchronous electricity generation characteristics by microbial fuel cell

A microbial fuel cell (MFC) was built using glucose as simulated domestic wastewater, using carbon felt as anode and activated anaerobic sludge as inoculum, which came from a sewage treatment plant. The sewage was treated and electricity was generated synchronously. The effect of substrate concentration and operating temperature on electrode process kinetics was examined. The relationship among electrochemical activity of microbes, charge transfer resistance, anode potential, and capacity of producing electricity was explored. The main conclusions about sewage-fuel MFC are summarized as follows: The relationship between the peak power density and substrate concentration followed Monod enzyme kinetics equation P=Pmaxc/(ks+c), with a maximum power density (Pmax) of 320.2 mW/m2 and half-saturation concentration (ks) of 138.5 mg/L. When the initial glucose concentration is less than 2000 mg/L, the reaction follows the first order kinetics equation: −dcA/dt=kcA, k=0.262 h−1. Increasing the temperature from 20 to 35°C, the charge transfer resistance decreases from 361.2 to 36.2 Ω, the anode electrode potential also decreases, while peak power density increases from 80.6 to183.3 mW/m2. At 45°C, the electrochemical activity of microbes declines, and the peak power density decreases to 36.8 mW/m2. After operating steadily for 6 h, coulombic efficiency and COD removal efficiency reach a maximum of 44.6% and 49.2%, respectively, at 35°C with the substrate concentration of 1500 mg/L.

Characteristics of electricity generation and biodegradation in tidal river sludge-used microbial fuel cells

The electricity generation behavior of microbial fuel cell (MFC) using the sludge collected from the riverbank of a tidal river, and the biodegradation of the sludge by the electricity generation are evaluated. Although the maximum current density (150-300 mA/m(2)) was higher than that of MFC using freshwater sediment (30 mA/m(2)), the output current was greatly restricted by the mass transfer limitation. However, our results also indicate that placing the anode in different locations in the sludge could reduce the mass transfer limitation. After approximately 3 months, the removal efficiency of organic carbon was approximately 10%, demonstrated that MFC could also enhance the biodegradation of the sludge by nearly 10-fold comparing with the natural biodegradation. We also found that the biodegradation could be identified by the behavior of oxygen consumption of the sludge. Importantly, the oxygen consumption of the sludge became higher along with the electricity generation.

Influence of Dirt on the Lens and Yellow Sand to Electricity Generation Characteristics of a Concentrator PV System

Influence of Dirt on the Lens and Yellow Sand to Electricity Generation Characteristics of a Concentrator PV System

Performance of denitrifying microbial fuel cell subjected to variation in pH, COD concentration and external resistance

The effects of pH, chemical oxygen demand (COD) concentration and external resistance on denitrifying microbial fuel cell were evaluated in terms of electricity generation characteristics and pollutant removal performance. The results showed that anodic influent with weakly alkaline or neutral pH and cathodic influent with weakly acidic pH favored pollutant removal and electricity generation. The suitable influent pH of the anode and cathode were found to be 7.5-8.0 and 6.0-6.5, respectively. In the presence of sufficient nitrate in the cathode, higher influent COD concentration led to more electricity generation and greater pollutant removal rates. With an anodic influent pH of 8.0 and a cathodic influent pH of 6.0, an influent COD concentration of 400 mg/L was deemed to be appropriate. Low external resistance favored nitrate and COD removal. The results suggest that operation of denitrifying microbial fuel cell at a lower external resistance would be desirable for pollutant removal but not electricity generation.