Electrical Requirements Research Articles

Thermally Conductive Polymer Composites with Hexagonal Boron Nitride for Medical Device Thermal Management

Polymer composites with hexagonal boron nitride (hBN) have the potential to meet the heat dissipation and electrical insulation requirements of electronic and medical devices. In this study, hBN/polymer composites were fabricated with thermoplastic polyurethane (TPU) and epoxy as matrix materials. Three hBN powder types (BN1, BN2, BN3) with different platelet sizes and degrees of agglomeration were used. BN1 (with average size of 1 μm) and BN2 (with average size of 12 μm) mainly contained hBN platelets, while BN3 (with average size of 20 μm) contained both platelets and agglomerates of platelets. BN2 gave the highest thermal conductivity, while BN1 gave the lowest thermal conductivity. Thermal simulations were performed for a medical device with a limit for the maximum surface temperature. For the encapsulation of this device, several material combinations were simulated, using anisotropic thermal conductivity data. This included encapsulations with inner layers of commercial thermally and electrically conductive materials and an outer layer of the best thermally conductive (and electrically insulating) hBN/TPU composite fabricated by the authors.

Investigating the energy storage performance in optimal design of a solar hybrid multi‐generation system with distillatory

AbstractIn this study, a cogeneration system of heating, cooling and power used with the solar flat plate collectors (FPCs) and photovoltaic panels (PVs) integrates with a multi‐effect distillation through thermal vapor compression (MEE‐TVC), investigated as the first system to meet the loads of heating, cooling, electricity and fresh water. As an innovation, the combination of the first system with cooling and thermal storage tanks have been investigated. The systems are optimized with MATLAB and single‐objective genetic algorithm. The total annual cost considered as the objective function to compare the two systems and 36 and 61 design variables are obtained for the first and second systems, respectively. The design parameters considered for optimization included the capacity of the diesel engine as the prime mover, electrical chiller capacity, absorption chiller capacity, size of the boiler, partial loads of the diesel engine for each hour of the 2 days (1 day for hot months and 1 day for cold months), partial loads of the chillers for each hour of the first days (second day has no cooling load), number of FPCs and PVs, number of effects in the desalination unit, driving steam pressure, feed water flow rate, driving steam flow rate, and electric cooling ratio. The optimization aimed to fulfill the heating, cooling, electricity, and fresh water requirements of a residential town situated in Bandar Abbas, Hormozgan province, Iran. The second system's optimization results were compared with first system. The results have shown that the objective function for the first system was and the initial investment cost was , and for the second system the objective function was and the initial investment cost was . Therefore, by using energy storage, the objective function was reduced by 11.30%.

Enhancing Semiconductor Package Reliability through Mechanical Property Optimization of Pressureless Sintering Die Attach Adhesives

There is growing demand for high-power devices, wide bandgap SiC and GaN semiconductor materials in semiconductor market, and a drive to integrate die attach materials that can replace lead-containing solders. However, epoxy-based and solder materials face challenges to meet high thermal conductivity and survive elevated working temperatures. Pressure-assisted silver sintering has overcome these challenges, but downsides of pressure-assisted silver sintering are that it requires special equipment and for some applications, packages are unable to withstand the pressure required to facilitate sintering. Pressureless sintering materials could be processed using the same equipment as traditional die attach adhesives. It develops strong metal bonds to substrates, providing high thermal conductivity and withstanding high temperatures. However, compared to pressure-assisted sintering, pressureless materials may have difficulties to form a dense bondline structure if the formulation design is not optimized. Moreover, once the sintered structure is built during cure, further bondline reduction may induce additional stress. Therefore, it is critical that the pressureless sintering material’s mechanical properties are formulated to effectively manage stress and pass all reliability testing – especially for automotive packages. This paper will present the findings from a study that evaluated the impact of various formulation components – such as silver packing and resin chemistry – on the mechanical properties and interfacial bonding of pressureless sintering die attach adhesives. The effect on in-package reliability performance was also investigated to better understand material properties that can pass reliability testing while maintaining high thermal and electrical conductivity adhesive requirements.

Techno-economic configuration of an optimized resident microgrid: A case study for Afghanistan

The escalating demand for electricity and the imperative to reconstruct underprivileged areas in Afghanistan necessitates a resilient energy supply system. This study advocates for the implementation of a cost-effective and high-performing microgrid in a region situated in the northern of Kandahar City, Afghanistan. Utilizing a mix of diesel engines, batteries, wind, and solar energy sources, the microgrid aims to provide a sustainable and eco-friendly solution to meet the electricity requirements. Employing the HOMER software for comprehensive analysis, the proposed microgrid configuration comprises a 3.69 kW PV, a 1.50 kW diesel generator, and 27 units of 1 kWh LA batteries. The study investigates six different configurations to identify the optimal solution based on community-specific criteria. Factors such as energy generation, cost, and system performance are rigorously evaluated by the software, culminating in the selection of components that constitute the hybrid system. The optimal configuration includes a capital cost of 5962 $, a net present cost (NPC) of 10108$, operating and maintenance (O&M) costs amounting to 320.69$, and a cost of energy (COE) at 0.190$/kWh. These results show the viability and economic feasibility of the proposed microgrid as a sustainable energy solution for the studied community in Afghanistan.

Tailored laser beam shapes for welding of copper using green laser radiation

AbstractThe rapid development of laser beam sources and adapted welding technologies in recent years lead to an increased use of laser welding techniques in automated production nowadays. Especially its precision and local energy input are key features for joining applications in electric vehicle components, where joints have to meet both mechanical and electrical requirements as current-carrying connections. However, the copper materials used are difficult to weld due to their physical properties, making a stable process with fewest seam imperfections only feasible within a limited process window. Recently available beam sources emitting visible laser radiation have proven to overcome the low absorptivity at process start, but spattering is still a prone defect significantly affecting process efficiency and quality. Literature approaches for modifying the energy input point to laser beam shaping as a method for reducing process imperfections, which, however, has not been extensively researched in copper processing using green laser radiation.Thus, this study investigates the influence of a shaped intensity profile for visible laser radiation created with a reflective diffractive optical element in laser beam welding with laser powers up to 3 kW. A characterization of the process dynamics is performed by use of high-speed imaging, and metallographic analysis is used to elaborate benefits of the applied beam shapes. With beam shaping, an enlarged heat conduction welding regime and an advantageous seam shape are found. Furthermore, a decrease in spatter formation during deep penetration welding is detected for the elliptical beam profile, which correlates with an oscillation movement of the capillary.

New generation B-Field and RAD-tolerant DC/DC power converter for on-detector operation

The increase in the number of readout channels in new detectors, like the Micro Pattern Gas Detectors (MPGD), in the order of several millions, requires a large amount of electrical power to supply the front-end electronics, up to hundreds kW. If this power is generated at long distances from the detector, the voltage drop on the connection cables puts serious constraints to the supply current, to the wire cross-section and to the power distribution. A large amount of voltage drop on the cables, apart an increased power dissipation on wire resistance, determines regulation issues on the load in case of current transients. To mitigate these problems, a new generation DC/DC converter, working in a heavily hostile environment and with a power density greater than 200 W/dm3, was developed. It is modular, with up to four independent modules, eight channels each, collected in a water-cooled crate, and can supply the load with an adjustable 10 to 12 V output up to 170 W per channel. In this contribution, the design constraints of such a converter are analysed, taking as a basis the environmental, electrical and mechanical requirements of the ATLAS New Small Wheel (NSW) project. Thermal considerations require the converter to be water-cooled, and the dimensional constraints impose the adoption of an innovative design to convey the dissipated heat towards the heat exchanger. The control and monitoring system allows for the full remote management of the converter. Main electrical parameters were measured and are reported. The converter was also characterized in a harsh working environment, with radiation tests in the CERN CHARM facility beyond the limits estimated for ten years operation in ATLAS, and with magnetic field tests in various orientations, using different magnets at CERN up to 1.3 T. A better common mode noise filtering design improvement was implemented after the first characterization. Final performance measurements after the modifications are also reported.

PERANCANGAN SISTEM INFORMASI PENCATATAN DAN PERHITUNGAN TAGIHAN KWH METER LISTRIK PASCA BAYAR DI PT. MAHIZA KARYA MANDIRI

Electrical energy requirements have increased in line with economic growth and social welfare. Every month, meter recording officers come to record customers' electricity kwh usage. Problems often occur in the recording process using the ACMT application such as errors in inputting the booth meter numbers or the customer's kwh meter as recorded by the officer. The main problem of this research is how to design a system for recording and calculating postpaid electricity kwh meter bills to produce a report that is fast, accurate, and optimal. This research aims to design a postpaid electricity meter recording system that will provide bill estimates for the customers, and reduce complaints and spikes in customer bills due to recording errors. The design created was tested using the White Box and Black Box Testing method as the results worked according to its function defined.

River Hydrology Analysis For Micro Hydro Power Plant

The Micro Hydro Power Plant (PLTMH) is a generator capable of fulfilling the electrical requirements of isolated regions. PLTMH serves as an alternative means of generating electrical energy for the community. This power facility offers numerous advantages, particularly for remote areas across Indonesia. Water is a crucial energy resource due to its ability to generate electricity, a cost-effective and environmentally friendly kind of energy. The micro-hydro type PLTMH (0.5–100 kilowatts) in Aceh Province is the Lhoong PLTMH, which was built with assistance from PT. Coca-Cola in 2005. This PLTMH is located in Krueng Kala Village, Lhoong District, Aceh Besar Regency. This research aims to determine the availability of the Krueng Kala Lhoong PLTMH's flow rate and the availability of power and energy produced by the Krueng Kala Lhoong PLTMH to meet the electricity needs of Lhoong residents. It is hoped that the benefits of this research will be able to provide development and knowledge, especially in the field of pyrotechnics, and can become reference material for further study, providing information about micro hydropower plants, especially the Krueng Kala Lhoong PLTMH. The research utilizes the Pearson III Log Method to calculate maximum rainfall frequency and Fj Mock for reliable discharge calculation. The research results showed that the full rain discharge with a return period of 25 years was 1152.68 mm/hour. The total potential evapotranspiration (ET0) value occurred in March, reaching 6,649 mm/day. The mainstay discharge with a probability of 85% is Q85% = 0.24 m3/second, obtaining power of 27,914 kW and energy for a year of 20787,644 kWh. The calculation results conclude that the Krueng Kala power plant is still classified as a PLTMH, producing power below 100 kW and generating an annual energy of 20,787,644 kWh. The electricity can be distributed to Meunasah Krueng Kala Village, Baroeh Krueng Kala Village, Tunong Krueng Kala Village, and small enterprises in these three communities.

Component Modification and Data Communication Lines of Automatic Crop Sprinklers on Soil Moisture-Based Agricultural Land

Plants are living things that need water for their growth. This research was carried out designing, making, and developing tools that previously existed. This development focuses on how to communicate between microcontrollers and aims at the needs of large and open land. Where in previous studies the coverage area was only the area around the radius of the wifi router and the coverage will be increased again using NRF24L01. In previous studies using relays on the solenoid valve will be replaced using Mosfet LR7843 which has lower electrical power requirements. This system uses the Wemos D1 Mini and Arduino Uno as its microcontroller, where data from sensors in the system in the Arduino Uno will be sent using NRF24L01 and received by NRF24L01 on the Wemos D1 Mini. Then the data that has been received will be processed and sent to the internet and can be monitored through the Blynk application which can see temperature conditions, air humidity and soil moisture. From the test results, the average difference obtained at a temperature reading of 0.44 ° C and air humidity of 3.2%, and when the humidity reaches >50% the solenoid valve can open automatically. The distance that can be reached when testing as far as ±20 meters can be due to the test site being blocked by walls.

Numerical Study on Peak Shaving Performance of Combined Heat and Power Unit Assisted by Heating Storage in Long-Distance Pipelines Scheduled by Particle Swarm Optimization Method

Thermal energy storage in long-distance heating supply pipelines can improve the peak shaving and frequency regulation capabilities of combined heat and power (CHP) units participating in the power grid. In this study, a one-dimensional numerical model was established to predict the thermal lag in long-distance pipelines at different scale levels. The dynamic response of the temperature at the end of the heating pipeline was considered. For the one-way pipe lengths of 10 km, 15 km and 20 km, the response times of the temperature at the distal end were 2.33 h, 2.94 h and 3.54 h, respectively. The longer the flow period, the further the warming-up time is delayed. An optimization scheduling approach was also created to illustrate the peak shaving capabilities of a CHP unit combined with a long-distance pipeline thermal energy storage component. It was demonstrated that the maximum heating load of the unit increased up to 503.08 MW, and the heating load could be expanded in the range of 17.88 MW to 203.76 MW at the minimum electric load of the unit of 104.08 MW. Finally, the particle swarm optimization method was adopted to guide the operating strategy through a whole day to meet both the electric power and heating power requirements. For the optimized case, the comprehensive energy utilization efficiency and the exergy efficiency increase to 64.4% and 56.73%. The thermal energy storage applications based on long-distance pipelines were simulated quantitively and proved to be effective in promoting the operational flexibility of the CHP unit.

A Computational and Experimental Performance Analysis of an Electromagnetic Voltage Regulator Proposal throughout Controlled Series Voltage Injection

Power quality problems related to short or long time voltage variation have motived the search for voltage compensator techniques capable to provide dynamic voltage regulation to accomplish voltage supply levels in accordance with electrical energy agencies acceptable levels. Although one could recognize that a variety of products already offered in the market are capable of attending general electrical power system requirements the available technology comprises quite simple devices till very sophisticate ones. Having in mind the combination of simplicity, competitive cost, low maintenance need and an attractive performance at recovering the voltage deviations, then an electromagnetic concept to restore the desirable voltage within the established voltage levels is here proposed. The control strategy to be used can provide properties that enable this new device at proving the time response in accordance with the needs for long term and short term voltage variations. Concerning the proposed compensator physical topology it consists in extracting the necessary electrical power throughout a shunt transformer and the injection via a series unit. Besides the arrangement, the paper goes further by establishing a computational time domain model and a laboratory experiment to highlight the overall structure effectiveness at compensating voltage changes.

Offshore wind energy potential along the Indian Coast considering ecological safeguards

This study focuses on assessing the offshore wind energy potential along the Indian Coast over a 10-year period (2005–2014) using high-resolution data from the simulation of the Weather Research and Forecasting (WRF) model. The predicted wind fields are utilized to identify potential sites, estimate offshore wind technical potential at different depths (ranging from 30 to 200 meters), and develop wind energy blocks within the Indian Exclusive Economic Zone. To ensure environmental protection, environmentally sensitive areas have been excluded from the offshore wind potential sites. The gross technical offshore wind potential was estimated to be 3941 GW within depths of 30–200 meters, excluding environmentally sensitive areas within the 0 to 30-m depth range. High-potential sites have been identified in the coastal states of Gujarat, Maharashtra, Kerala, and Tamil Nadu. The environmental offshore wind potential across these identified sites (feasible OWE sites) along the Indian coast is estimated at 432.34 GW within the 30 to 200-m depth range (at 140 m AGL).According to the report by the Central Electricity Authority (CEA), the predicted offshore wind power has the potential to significantly contribute to the country's total electrical power requirement for 2020–21. This study encourages exploration of offshore wind energy possibilities along the Indian coast and highlights the management challenges at suitable sites, including addressing potential conflicts between offshore wind energy development and other marine uses. The findings of this study can assist in the assessment of offshore wind resources and provide decision-makers with scientific evidence for the development of offshore wind energy in India, while also considering the management and conservation of marine ecosystems.

Effects of Cavity Depth of Glass Facades on Energy Performance of the Office Building Facade Scenarios of Dhaka City, Bangladesh

The concern of warming brought on by extreme solar radiation entering the glazed façade may become serious in Bangladesh, where high-rise buildings now commonly use these systems. This scenario will lead to higher energy usage since there will be a greater requirement for electricity to cool the indoor environment. Determining the effects of the Cavity Depth of Glass facades on the energy consumption of office buildings in Dhaka, Bangladesh, is the primary goal of this study. To establish techniques for optimization, different cavity depths, and other glazed façade system parameters have been proposed. Results were obtained by modelling the variables of the investigation using the computer simulation software EnergyPlus. As per the findings of the study, glazed façade systems in Dhaka may benefit greatly from a cavity depth of 1000 mm combined with bronze laminated glass. The glass façade's thermal performance is enhanced under the ideal cavity system since there is a discernible drop in the building's annual end-use energy of about 12.28 % and a drop in indoor temperature of roughly 2°C.

Nanoporous graphene-based thin-film microelectrodes for in vivo high-resolution neural recording and stimulation

One of the critical factors determining the performance of neural interfaces is the electrode material used to establish electrical communication with the neural tissue, which needs to meet strict electrical, electrochemical, mechanical, biological and microfabrication compatibility requirements. This work presents a nanoporous graphene-based thin-film technology and its engineering to form flexible neural interfaces. The developed technology allows the fabrication of small microelectrodes (25 µm diameter) while achieving low impedance (∼25 kΩ) and high charge injection (3–5 mC cm−2). In vivo brain recording performance assessed in rodents reveals high-fidelity recordings (signal-to-noise ratio >10 dB for local field potentials), while stimulation performance assessed with an intrafascicular implant demonstrates low current thresholds (<100 µA) and high selectivity (>0.8) for activating subsets of axons within the rat sciatic nerve innervating tibialis anterior and plantar interosseous muscles. Furthermore, the tissue biocompatibility of the devices was validated by chronic epicortical (12 week) and intraneural (8 week) implantation. This work describes a graphene-based thin-film microelectrode technology and demonstrates its potential for high-precision and high-resolution neural interfacing.

Investigation on plasma ionization process of a micro-cathode arc thruster

Micro-cathode arc thrusters (μCATs) are space propulsion options suitable for microspacecraft, and have recently attracted much attention because of their low electrical power requirements and simple, compact propellant systems. The plasma ionization process, however, is not currently well understood. In this study, a μCAT prototype was designed with the use of different specific materials for each component, enabling the study of the ionization process from the emissive light of excited and ionized states from different elements. ICCD emission spectroscopy and scanning monochromator measurements are conducted inside the electrode channel of a μCAT with a coaxial configuration. The excited state atomic spectral results and ionization state spectral results give us a comprehensive understanding of the behavior of neutral particles and ions during the discharge process of the μCAT. The ionization sequence follows in the order of C+, Al+, Ti+, Cu+, and Ti2+. From the duration of the spectral lines, C I has the shortest duration (16.9 μs), which shows that the ablation of the conductive film is mainly concentrated during the first half of the discharge, while anode and cathode ionization occur over the entire discharge duration. Additionally, Al+ ionization is observed during the discharge process, showing that part of the discharge energy is expended in ionizing the thruster outer shell, resulting in efficiency loss. An ionization ratio of k is proposed in this work to represent the relative ionization of the conductive film and cathode material, aiding us in determining the optimal operation conditions for lifetime extension.

Optical, Mechanical and Electrical Characteristics of Thermal Uncooled Bolometric Type Detector Based on Vanadium Oxide

Determination of optical, mechanical and electrical characteristics is one of the decisive factors in the design of instrumentation structures of thermal uncooled bolometer-type detectors (microbolometers). The paper presents the results of optimization calculations by means of computer simulation of absorption, transmittance and reflection spectra of device structures of microbolometers based on thermosensitive vanadium oxide film by finite-difference time-domain method (FDTD). The characteristics of the investigated microbolometer structure were checked for compliance with mechanical and electrical requirements for this class of devices.

Optimizing electrocoagulation pre-treatment efficiency during simultaneous treatment of different produced water streams in a FO-MD hybrid system

In this study, the electrocoagulation (EC) process was explored and optimized for the pre-treatment of key contaminants present in hyper-saline produced water (PW) streams before their treatment through forward osmosis-membrane distillation (FO-MD) hybrid system. Due to their hyper-saline nature and the associated high temperatures, PW streams can be treated cost-effectively and sustainably using low-pressure dual membrane filtration systems like FO-MD hybrids. Desalter effluent (DE) stream was used as the FO feed solution, and WOSEP outlet (WO) stream served simultaneously as the FO draw solution and MD feed solution. The key foulants were identified in the WO and DE streams. Silicon, calcium, and sulfur were found as the key elements contributing towards FO and MD membrane fouling in the form of CaSO4, SiO2, and CaSiO3. Applying EC for 10 min with 100 mA current (7 mA/cm2 current density) at a neutral pH of 7 demonstrated the highest removal efficiencies for silicon (97 %), calcium (3.6 %), and sulfur (12.2 %) with only 0.023 kWh/m3 electric energy requirement. FO-MD hybrid efficiency was re-assessed with pre-treated WO and DE streams. The FO flux showed more stability and increased by 32.5 % and MD by 28.9 %, with a 10 % reduction in specific reverse solute flux. EC is thus a robust and effective process for hyper-saline hazardous PW pre-treatment and can substantially improve the FO-MD hybrid system efficiency.

Optimal Planning of Urban Building-Type Integrated Energy Systems Considering Indoor Somatosensory Comfort and PV Consumption

Building energy consumption is the main urban energy consumption component, which mainly serves people-centered work and living energy demands. Based on the physical requirements of humans in urban buildings and to determine the comfortable body temperature in each season, this paper establishes a sizing optimization model of building-type integrated energy systems (IES) for sustainable development, where the cooling and heating loads required to maintain indoor somatosensory body comfort temperature are calculated. Depending on the external energy price, internal power balance, and other constraints, the model develops an optimal sizing and capacity-planning method of energy conversion and storage unit in a building-type IES with PV generation. The operating principle is described as follows: the PV generation is fully consumed, a gas engine satisfies the electric and thermal base load requirements, and the power system and a heat pump supply the remaining loads. The gas price, peak-valley electricity price gap, and heat-to-power ratio of gas engines are considered important factors for the overall techno-economic analysis. The developed method is applied to optimize the economic performance of building-type IES and verified by practical examples. The results show that using the complementary characteristics of different energy conversion units is important to the overall IES cost. A 300 kW building photovoltaic system can reduce the gas engine capacity from 936.7 kW to 854.7 kW, and the annual cost can be approximately reduced from 7.82 million to 7.50 million RMB yuan.

Performance Test, Noise, and Economic Analysis of Coffee Roasting Machines Rotating Cylinder

The roasting process carried out in this study was at the medium roast level, using a rotating cylindrical coffee roasting machine that used an electric heat source. This research aims to determine the performance and economic analysis of a rotating cylinder coffee roasting machine. Descriptive analysis in this study includes coffee roasting machine performance data (roasting temperature, moisture content, electrical energy requirements and noise) and economic performance data (NPV, IRR and BCR). The results of observing the performance of the machine obtained a roasting temperature of 205°C and a moisture content of 4.42%, in accordance with the Indonesian national standard (SNI) and the need for electrical energy in the heater was 3.18 kWh and in the motor of electric was 1.17 kWh. In this study, the noise analysis obtained showed the number 90 dB, which means it is less effective for operators in that environment. Meanwhile, the results of the economic analysis were obtained NPV, IRR and BCR respectively are IDR 225,363,266; 21.6 %; 5.18.

Pengangkut Muatan Kapasitas 2 kg Berbasis Mikrokontroler

Energy transformation is growing, and trade is becoming more complex and dynamic regarding energy efficiency and flexible production design. The development of a semi-automatic transporter aims to improve intralogistics' flexibility whereas the electrical power requirements and time efficiency can be analyzed. The analysis method measures the rotational speed of the semi-automatic transport wheel and identifies its model. The rotation speed of the wheels on a semi-automatic transporter is based on translational movement, rotary movement, and transport and load. The measurement results show that the energy requirements for translational and rotational movements increase due to the mass of the charge. However, in the same situation, an increase in the speed value of the semi-automatic transporter results in lower energy requirements, even though the need for electrical power is increasing. The capacity of the DC motor decreases with increasing load, namely from 239.184 rpm to 166.204 rpm, and likewise for the battery from 20000 mhA to 5400 mhA. In dynamic measurement conditions, namely, measurements made while the motorbike is running, there is an average measurement error of –0.11 cm to –0,03 cm in backward movements.