High-voltage Electrical Energy Research Articles

Research on automatic detection of gradual fault of high voltage electric energy metering transformer based on fuzzy rough set and whale optimization algorithm

Based on fuzzy rough set and whale optimization algorithm, the automatic fault detection method of high-voltage electric energy metering transformer is studied to improve the fault diagnosis effect and efficiency. On the basis of constructing the mathematical model of gradual fault of high-voltage electric energy metering transformer, the fuzzy rough set theory is used to reduce the data attributes of fault samples, eliminate similar attributes, determine the minimum fault feature set, and complete the fault feature selection, which is used as the input of the fault detection model based on Whale Optimization Algorithm-based Support Vector Machine (WOA-SVM). After the kernel parameters and penalty factors of SVM are optimized by whale optimization algorithm, the type of gradual fault of high-voltage electric energy metering transformer is identified. The experimental results show that the reduced fault attributes are distributed differently in the sample data, and the fault detection accuracy can be improved by 9.5 % through fault feature selection. The fault diagnosis model with Gaussian radial basis function, kernel parameter of 0.05 and penalty factor of 10 has the best performance. This method can identify the gradual fault types of high-voltage electric energy metering transformers, and the fault diagnosis effect is outstanding.

Triboelectric negative air ion generators for efficient membrane fouling control

Effectively controlling membrane fouling is critically important for enhancing the lifespan of membrane materials and reducing operational costs. This paper introduces a novel approach to control the fouling of gas–solid separation ceramic membranes using a triboelectric negative air ion (NAI) generator. The triboelectric NAI generator mainly consists of a roller-coupled rolling belt triboelectric nanogenerator (RCB-TENG), a boosting circuit, and a NAI emission head module. The RCB-TENG is used to harness the waste kinetic energy in the circular pipeline, and the boosting circuit converts it into high-voltage electrical energy to drive the NAI generator. This study investigated the effects of membrane fouling control, revealing a significant reduction in membrane pressure drop rate by 51.2 % and a decrease in the rate of flux reduction by 78.1 % upon using a triboelectric NAI generator. The backwashing regeneration of the membrane was notably enhanced. The mechanism of membrane fouling control was investigated and it was found that the main control method was through regulating the charge, morphological evolution, and migration characteristics of moving particles. This strengthens the interception and capture on the membrane surface, weakens the inertial collision and diffusion capture effects within the membrane, thereby controlling membrane fouling. This study provides a new perspective for effectively controlling membrane fouling.

Pulse power plasma stimulation: A technique for waterless fracturing, enhancing the near wellbore permeability, and increasing the EUR of unconventional reservoirs

The inherent characteristic of unconventional and ultra-low permeability reservoirs is a small drainage area that negatively affects the production rate and ultimate recovery (UR). Drilling horizontal wells, coupled with a stimulation process such as hydraulic fracturing, are applied to wells in these reservoirs to enhance well productivity. Although hydraulic fracturing has been the most famous stimulation technique in these reservoirs and has contributed to the increased US oil and gas production during the last several years, other stimulation techniques may be competitive with (or complementary to) hydraulic fracturing. This is because the main contribution to production in these reservoirs would be from complex fracture networks (often micro-cracks) combined with enhanced formation permeability rather than the classical two-wing fractures. Hence, a near-wellbore stimulation technique for improving the permeability of these reservoirs by activating the existing natural fractures and creating secondary microfractures would be highly desired. This paper investigates the pulse plasma stimulation technique to investigate such an approach of waterless stimulation/fracturing that creates multiple fractures and is also a permeability enhancement method. In this method, plasma is generated by discharging a high voltage and high current electrical energy in a very short time into two electrodes submerged in a wellbore filled with aqueous fluid. This study is divided into two sections. The first part presents experimental and numerical examples of stimulation/fracturing induced by pulse plasma in different rocks. Several parameters, including the effect of discharge with and without wire, input energy, confining stress, and rock type, on the induced fractures are studied. The second part uses the insights and results from the first part to numerically investigate pulse plasma's effects on production. Measurement of the formation permeability around the generated fractures indicated that the shock wave generated multiple fractures and increased the rock permeability by more than one or two orders of magnitude. The second part of the numerical section discusses the increased estimated rate and ultimate recovery (EUR) of horizontal wellbores due to fracturing and modified permeability resulting from pulse plasma. We present a sensitivity analysis on the magnitude and extent of the improved permeability region and its impact on EUR.

Research on Intelligent Verification System of High Voltage Electric Energy Metering Device Based on Power Cloud

To address the issues of low efficiency, poor security, insufficient compatibility, and difficulties in traceability associated with high-voltage electric energy metering (HVEEM) device verification methods, this paper proposes a design scheme for a remote verification system (RVS) of such devices based on a power cloud platform (PCP). The system adopts the concept of “high-precision local sampling + remote cloud verification” and develops a local acquisition device with compatibility and high precision to achieve fast acquisition of local electrical parameters. The IEC 61850 communication modeling is utilized to establish unified communication standards between the local device and the PCP. The PCP provides two verification methods: physical error verification based on a multi-channel standard and digital verification based on an improved Backpropagation (BP) neural network simulation model. Leveraging the advantages of power cloud technology, the system enables functions such as electrical energy calculation, remote intelligent error verification, cloud storage, condition monitoring, and early warning. Through testing and application, it has been demonstrated that the system achieves an integration accuracy level better than 0.02. It also exhibits good security, compatibility, and traceability of measurement values while attaining a high level of informatization and intelligence. Particularly, the system shows promising prospects for the remote and efficient verification of large-scale and multi-type high-voltage metering devices.

Characteristic Analysis of Cascading-Combination DC/DC Controlled-Source Circuit for Marine Electromagnetic Transmitter

Nowadays marine electromagnetic method is a geophysical method which can effectively explore natural gas hydrate (NGH) resources. This method acquires seafloor structure and distribution laws of mineral resources by transmitting high-power electromagnetic waves to the seafloor, and its detection depth relies on intensity of transmitted electromagnetic waves. At present, marine electromagnetic transmitter is inappropriate for transmission of high-power electromagnetic waves, and therefore, a novel DC/DC controlled-source circuit formed by input-series and output-parallel ZVZCS DC/DC controlled-source circuit units was proposed in this paper, and thus transformation of high-voltage and high-power electric energy was realized by using switching devices with low rated voltage and rated current. Common duty ratio control is adopted to construct small-signal mathematical model of cascading-combination ZVZCS DC/DC controlled-source circuit, influences of parameters on voltage balance at input side and current balance at output side are analyzed. Simulation and experimental results verify that the proposed circuit has favorable voltage and current sharing effect and could satisfy deep exploration requirements of marine electromagnetic transmitter with high transmission voltage.

Design and Implementation of a Tether-Powered Hexacopter for Long Endurance Missions

A tether-powered unmanned aerial vehicle is presented in this article to demonstrate the highest altitude and the longest flight time among surveyed literature. The grid-powered ground station transmits high voltage electrical energy through a well-managed conductive tether to a 2-kg hexacopter hovering in the air. Designs, implementations, and theoretical models are discussed in this research work. Experimental results show that the proposed system can operate over 50 m for 4 h continuously. Compared with battery-powered multicopters, tether-powered ones have great advantages on specific-area long-endurance applications, such as precision agriculture, intelligent surveillance, and vehicle-deployed cellular sites.

Identification Damage of PMT 500KV BAY 7A1 Using the Breaker Analyzer and Contact Resistance Methods at the Substation

One of the state-owned companies in the electricity sectors, located in South Bandung with the main function of managing distribution installation assets (Transmission and Substation) and maintenance of distribution installation assets to maintain the continuity of efficient and reliable distribution of high voltage electrical energy. In substations, PMT is the most important component, coordination between PMT divisions must be paid more attention. One of the disturbances in PMT is the high value of contact resistance and it is not synchronous during the Open-Close process. The research was aimed to identify how much the value of contact resistance at each PMT, and how much loss of conductivity of PMT and also carried out simultaneous testing to observe the level of synchronization between phases. After various tests were carried out, by looking at the results of these tests, it could be concluded that the PMT 7A1 had no damage, and could still operate normally. Then, the purpose of maintaining high voltage electrical equipment is to ensure the continuity of electricity distribution and ensure reliability, and to extend the life of the equipment by reducing equipment damage.

A Wideband Magnetic Frequency Up‐Converter Energy Harvester

The cover illustrates a wideband mechanical energy harvester that utilizes street vibrations to power a traffic light. When this wideband harvester is placed in a vibrating environment, it converts the ambient vibrations into high-voltage electrical energy. This energy can then be used to power various sensors and electronics. Further details can be found in the article, number 2001364, by Abdullah S. Almansouri, Khaled N. Salama, and co-workers.

Effect of dehydrofluorination reaction on structure and properties of PVDF electrospun fibers.

Piezoelectric nanosensors were prepared with a novel type of dehydrofluorinated poly(vinylidene fluoride) (PVDF) nanofibrous membrane. With the synergistic effect of the dehydrofluorination reaction and applied high voltage electric field, the piezoelectric and energy storage properties of fibrous membranes attained great improvement. It was found that the simultaneous introduction of conjugated double bonds to the backbone of PVDF which was accompanied with the elimination of HF, resulted in the decrease of its molecular weight, solution viscosity and hydrophobicity. The crystalline phase, diameter, piezoelectric and energy storage properties of electro-spun PVDF nanofiber membranes significantly depend on the degree of HF elimination in dehydrofluorinated PVDF. The dehydrofluorinated PVDF with 5 hours of reaction exhibits the highest discharged energy density (Wrec) and energy storage efficiency (η), but excessive dehydrofluorination reaction is unfavorable to the energy storage properties. In addition, the dehydrofluorinated PVDF fiber membrane-based nanosensor possesses a larger electrical throughput (open circuit voltage of 30 V, which is three time that of the untreated PVDF), indicating that the introduction of double bonds can also improve the piezoelectric properties of PVDF nanofibers.

A novel approach of high-voltage low-current electric energy input to synthesise cost-effective ultra-strong ductile material

ABSTRACT Adopting a unique electrical circuit design, here we treat a significant low-cost engineering material (eutectoid steel not containing costly alloying elements) with a high-voltage (100 kV) low-current (150 mA) energy input (energy level exceeding cohesive energy). A distinctive structural evolution is ascertained with treatment duration of only 5 min as an outcome of lamellar fragmentation and matrix supersaturation. This envisages an origin of dispersed nano-sized hard cementite spheroids embedded in nano-thick martensite crystals of stratified-tile-morphology along with distributed α-ferrite regions containing sub-microscopic cementite particles of various shapes. Apart from the conjoint effect of nano-scale dispersion strengthening and martensitic strengthening overhauling the effect of conventional lamellar strengthening on a gross scale; high dislocation density and systematically arranged dislocations of similar sign at incoherent cementite particle-matrix interface provides a unique combination of ultra-high strength (UTS ∼ 1.5 GPa), significantly high specific strength (188 MPa/g cm−3) and large ductility (%Elongation = 20). Therefore, in terms of the adopted synthesis route, structural evolution and mechanical property achieved, a new dimension is hereby added to the next-generation material development so as to meet the ever increasing demand for low-cost structural application. In turn, we elucidate a fundamental conceptualization for the first time which exemplifies disproportionate atomic migration at highly incoherent nano-sized cementite particle-martensite matrix interface in steel under high-voltage low-current energy input, resulting in accumulation of dislocations of similar sign so as to significantly enhance strength along with retention of substantial ductility.

Evolution of Electrical Behavior Due to Nanosilver Concentration Influence on Nanosilver-Doped Poly-Phenylene-Sulfide Polymer Conductor

Conductive polymers have been attracting increasing interest in recent years. Their properties such as corrosion resistance and moldability have shown their potential as an alternative production material to conventional metals such as copper and tin. Among those that have benefited from the application of conductive polymers are the semiconductor and microelectronics industry due to their low conductivity requirements. However, there are still some challenges in high voltage applications because of the limited charge transfer capabilities in high-energy transmission utilizing high-voltage electricity. This includes poly(1,4-phenylene sulfide) or PPS, which has had various dopants such as copper particles added to enhance the electrical properties. Silver is also known to be an excellent electrical conductor and, in nanoparticle form, could diffuse effectively into the polymer matrix and improve its electrical behavior. A set of experiments were carried out to study the organometallic behavior of nanosilver-doped poly(1,4-phenylene sulfide) (PPS) with six different mixing ratios. SEM micrographs have shown an interesting change in electrical properties in the overall polymer morphology. It was observed that there was a change in the electrical conductivity of the PPS as the concentration of nanosilver increased. The results from this study could contribute to the establishment of more effective parameters in the doping of PPS with nanosilver, and pave the way to the development of improved conductive polymers for high-voltage electrical energy transmissions.

Novel Detection Method of High Voltage Power Metering Circuit Fault based on Electric Energy Meter Phase and Voltage Transformer

The basic structure of the electromagnetic induction type voltage transformer is the core and primary, secondary winding. Characteristics of capacity are small and relatively constant. This paper introduces the application of electric energy meter, including two kinds of three-phase electric energy meter (three-phase two elements and three element phase) and non reactive energy meter. In this paper, the high voltage electric energy metering system of fault conditions is analyzed. The paper presents novel method of high voltage power metering circuit fault detection based on Electric energy meter phase and voltage transformer. The voltage circuit fault that electric energy meter pressure loss, less pressure fault detection method is analyzed.

High‐voltage electrical energy meter with measurement chips floating at 10 kV potentials

To overcome disadvantages of the conventional electric energy measurement system (CEEMS) in 10 kV distribution network, the study presents a high-voltage electrical energy meter (HVEEM) comprised of signal sensors, two measurement units, a synthesis unit, power supplies, and extended communication devices. With measurement chip circuit boards floating at 10 kV potentials, HVEEM accomplishes electrical energy measurement at the primary side. With the whole structure, HVEEM can be calibrated as a whole, and the synchronisation error makes no difference on its whole error. As the core component, the capacitive voltage divider (CVD) acts as not only the voltage sensor but also the power supply. The stability of CVDs, which is almost not affected by temperature, can be improved by the manner of voltage accelerated ageing for a certain time. CVDs for power supplies are able to output enough power for measurement chip circuit boards even if a single-phase ground or an opening fault occurs. The tests both in the laboratory and the field prove that HVEEM has substantial advantages over CEEMS especially in accuracy and reliability.

Histopathological Outcomes after Irreversible Electroporation for Prostate Cancer: Results of an Ablate and Resect Study

Irreversible electroporation is a tissue ablation modality that uses high voltage electric energy to induce an increase in cell membrane permeability. This causes destabilization of the existing cellular transmembrane potential leading to cell death, due to the inability to maintain cellular homeostasis. This phase I-II study was designed to evaluate the histopathological outcomes of irreversible electroporation to prostate and surrounding tissue in radical prostatectomy specimens. Sixteen patients with prostate cancer underwent an irreversible electroporation ablation without curative intent, followed by radical prostatectomy scheduled 4 weeks later. For histopathological examination of the prostate, whole mounted tissue slices were examined by dedicated genitourinary pathologists. The borders of the ablation zone and residual tumor were outlined on the slides. The irreversible electroporation ablation zones were characterized as areas of fibrosis, necrosis and loss of epithelial tissue in terms of denudation in the glandular structures. The ablation zone was well demarcated, showing trenchant delineations between viable and nonviable tissue. The ablated tissue showed mild to moderate inflammation, with atrophic cells in 1 case. The area was surrounded by hemorrhage at the location of the electrodes. No skip lesions or viable tissue was seen in the ablation zone. Fibrinoid necrosis of the neurovascular bundle was observed in 13 patients and denudation of the urothelium of the prostatic urethra was seen in 9. Histopathological assessment of the prostate 4 weeks after irreversible electroporation ablation showed sharply demarcated fibrotic and necrotic tissue in the ablation zone. No viable tissue was observed in the irreversible electroporation ablation zone.

Finite Element Modelling of Electro-hydraulic Forming of Sheets

High velocity sheet metal forming methods, such as electromagnetic forming and electro hydraulic forming (EHF), are based on high voltage electrical energy. This paper gives theoretical details about high strain rate forming in the Electrohydraulic forming process. Following the experimental results in the literature, a simulation of the high strain rate forming was prepared in ABAQUS-CAE wherein a dynamic loading on a sheet blank was applied and was allowed to plastically deform following the Johnson-Cook material model. The results of the simulation were validated from the experimental values obtained from existing literature. After the model was validated further simulations were carried out to obtain similar results for other commercially available materials like Al 6061 T6 alloy and Mg-Gd-Y alloy.

The Research of Novel High Voltage Electric Energy Measurement Apparatus Based on Three-Phase Four-Wire Virtual-Ground Theory

A novel apparatus is introduced in this paper used to measure high voltage electric energy based on three-phase four-wire virtual-ground theory. The virtual-ground design, Faraday shielding technique and Warner DC (Direct Current) self-supply method are integrated in this apparatus based on new I/V, V/V techniques to realize high accuracy, reliability and wide-linear range measuring. The effectiveness of the apparatus has been proved by in-house calibration and on-site test . The test result shows that it can be used in high voltage grid on-site calibration . Its measurement uncertainty can be limited to 0.1% under the condition of PF=1.0~0.8, and can reach 0.15% as PF=0.5. In summary, the apparatus discussed in this paper can be applied as high voltage electric energy measurement instrument to meet the requirement of online metrological verification and calibration. Furthermore, it is very useful for building the system of Advanced Metering Infrastructure (AMI) in smart grid.

Impact of Forging Conditions on Plasma Nitrided Hot-forging Dies and Punches

In this work an effort has been made to study the effect on the performance of the plasma nitrided AISI H13 hot-forging dies and punches in two different forging service conditions –namely, fully-automatic and semi-automatic processes. The plasma nitriding is performed to increase the surface properties like –wear resistance and surface hardness of these components. After plasma nitriding the surface hardness of these materials has increased typically from ~500 HV0.01 to ~1200 HV0.01. In the plasma nitriding process high-voltage electrical energy is used to form plasma through which nitrogen ions are accelerated to impinge on the workpiece. The ion bombardment heats the workpiece, cleans the surface, and provides active nitrogen to make iron-nitride compounds. The iron-nitride compounds then diffuse to the workspace to harden the surface. In these two service conditions the plasma nitrided hot-forging dies and punches have shown typically 2.5 to 4 times increment during the performance. It is observed that the increment in the performance of the dies and punches depends on the forging service conditions, i.e., temperature of the dies and punches, shot repetition time and effective cooling of dies and punches in service conditions. Four times increment in the performance of dies and punches is found in the semi-automatic process, whereas two and half times increment in performance of dies and punches is observed in the fully-automatic process.

Miniaturized g- and spin-activated Pb/HBF 4/PbO 2 reserve batteries as power sources for electronic fuzes

This paper discusses miniaturized Pb/HBF 4/PbO 2 reserve batteries (MRB) for military applications as in-flight power sources for small-caliber electronic fuzes, where the setback acceleration and high-spin force in firing environments are used to activate the MRB. The MRB is composed of a series configured 23 bipolar electrodes, an isolated glass ampoule filled with an electrolyte and an internal cutter for breaking the glass ampoule. The MRB is designed to furnish high-voltage electrical energy with a fast activation time in gunfire environments and must have a 20-year shelf life. The electrolyte volume is determined from the simulation results of a CFD program (FLUENT) for reduction in design time and cost. Two kinds of MRBs have been designed and fabricated: MRB-S with one narrow electrolyte-filling microchannel and MRB-D with two. In the experimental study, spin tests under 10,000 × g's and ∼20,000 rpm conditions and a fire test under 43,000 × g's and 57,000 rpm conditions have been made. The fabricated MRB with a diameter of 16 mm and a height of 13 mm has achieved a maximum voltage of 34.6 ± 0.4 V, an activation time of 8.6 ± 0.6 ms and a maximum capacity of 37.4 ± 0.4 W s at an optimized electrolyte volume of 180 mm 3. The test results have verified that the activation time of the MRB at a low temperature of −32 °C can be improved by decreasing the flow resistance of the electrolyte in spite of the decreased ion mobility.

Electroimpact Compaction of PM Components

AbstractAn explosive cartridge gun was used to accelerate a cylindrical impacter to a velocity of 120 m s−1 on to a powder specimen contained in a thick walled cylindrical die. The impacter also acted as a short circuit switch to discharge stored high voltage (up to 10 kV) electrical energy through the powder during the impact. In this way, relatively high density and tougher powder metallurgy components were obtained as compared with those from electrical discharge or impact processes applied individually. These compacts exhibited mechanical interlocking as a result of impact as well as interparticle welding due to electrical discharge. The steel impacters were partially insulated to vary the duration between the instant of electrical discharge and that of maximum compressive force. The best compact was found to be produced when the electrical energy was discharged at the instant just before maximum dynamic compaction pressure occurred. PM/0426

Direct conversion of CO2 laser energy to high-voltage electrical energy

Direct conversion of CO₂ laser energy to high-voltage electrical energy