Electric Technology Research Articles

Reducing the cost of home energy upgrades in the US: An industry survey

Decarbonizing the US residential building stock requires a substantial acceleration in home energy upgrades. Numerous barriers exist to accelerating adoption of efficient and electric building technologies, but foremost among these is high upfront costs. This study uses an industry survey delivered to a sample of home energy professionals to examine promising cost reduction strategies across a range of project types, including HVAC, water heating, and envelope/insulation projects. The survey included quantitative and qualitative questions to collect evidence on the estimated cost reduction potential of these strategies and their likelihood of use in the construction industry. The 167 survey respondents included contractors, energy consultants, architects, manufacturers, and others with experience in delivering energy upgrades in single-family and multifamily buildings in the US. Results show that significant cost reductions are achievable by minimizing additional infrastructure costs (such as replacing electric panels), streamlining project planning/management, and deploying innovations that simplify installation. We find that for a typical deep retrofit project, including heat pumps for space and water heating in addition to envelope upgrades, the strategies could result in a total installed cost reduction of nearly 50 %, dramatically improving the customer economics of such a project. This research makes a novel contribution to the literature on strategies to reduce the costs of residential retrofits. We discuss how our study's insights on the highest-value cost reduction strategies for home energy upgrades can further accelerate their uptake in the US housing stock.

Electric vehicle power system in intelligent manufacturing based on soft computing optimization

Soft computing technology has attracted extensive attention in computer engineering and automatic control domains because it can deal with uncertainties, fuzziness, and complex practical problems. This study adopts a Genetic Algorithm (GA) in soft computing technology to realize the cooperative optimization of electric vehicle's dynamic and economic performance. The advantage of soft computing technology lies in its adaptability to uncertainty, fuzziness, and complex practical problems, making GA an effective tool for solving complex optimization problems. Firstly, the electric vehicles' power system structure and energy management strategy are investigated and analyzed. Secondly, the improved non-dominated sorting genetic algorithm II (NSGA-II) is selected to optimize the parameters of electric vehicles because of its simple operation and high optimization accuracy. Thirdly, NSGA-II is used to construct the electric vehicles' power and energy configuration, with power and economic performance as the main optimization objectives. Meanwhile, a fuzzy logic controller is designed to adjust the parameters of GA online, so that the optimization process is closer to the actual operating conditions. Finally, the relevant variables are selected to achieve the optimization goal, the optimization objective function and constraint conditions are established, and the model is simulated and evaluated. The results show that the optimized electric vehicle's acceleration time is remarkably reduced, the dynamic performance is improved by more than 7 %, and the power loss is reduced by 5 %. In addition, compared with the current multi-objective optimization model, this model enables electric vehicles to travel longer distances under the same power. This study provides a new idea and method for the performance optimization of electric vehicles. Moreover, it offers a valuable reference for the innovation and development of electric vehicle technology in the intelligent manufacturing field. This study indicates that electric vehicles could be more efficient, energy-saving, and environmentally friendly to serve people's travel needs in the future.

Vibration reduction of an electric vehicle heat exchanger by controlling the polarization of its ferroelectric ceramics

The growing requirements in terms of CO2 emissions reduction in transports renders necessary the development of new electric traction technologies. This results in new technical constraints for equipment manufacturers, forcing them to reduce the acoustic emissivity of their new products inside and outside vehicles. Heat exchangers for electric cars are part of this new product category. High voltage supplied by the battery of electrical vehicles requires introduction of a new energy conversion process and technology. To this end, components based on ceramics containing barium titanate (BaTiO3) with high electrocaloric coupling properties are selected to provide the heating function. Baryum titanate is ferroelectric. This category of materials is subjected to piezoelectric and electrostrictive effects. The vibrations induced in the components (rods) containing the BaTiO3 ceramics are transmitted through the system, and cause undesired acoustic radiation. This coupling is a suffered effect and is not taken into account in the integration process during the rods manufacturing. In this study, an experimental characterization is proposed to identify the involved electromechanical coupling coefficients. Numerical simulations of the vibrations induced by BaTiO3 are carried out and used to study the possibility of attenuating them by controlling the polarisation of the ceramics or by geometric modifications.

Predicting noise and vibration in electric brake systems at mass production stage using q-axis current

This study explores the challenges of noise, vibration, and harshness (NVH) in electric brake systems within the context of the automotive industry's shift towards environmentally friendly technologies. The electrification of vehicles and their braking systems leads to weight reduction and enhanced braking efficiency. However, these advancements also yield new NVH challenges. The intricate motor-driven mechanisms of electric brake systems are prone to cogging torque, magnetic imbalance, and radial electromagnetic forces, which degrade the user experience and necessitate service interventions. Therefore, this study presents an approach to predicting noise and vibration levels using q-axis current measurements obtained during the initial actuation of electric brake systems in the mass production stage. This study aims to establish a predictive model that can identify potential NVH problems early, enhance the quality and reliability of electric brake systems, and improve user satisfaction. This method enhances sustainable vehicle technologies, improving the overall user experience. The study delves into the intricate relationship between electrical currents and NVH phenomena by integrating electromagnetic analysis with mechanical dynamics. Therefore, this paves the way for the development of advanced diagnostic tools in electric vehicle technology.

In Situ Forming Asymmetric Gel Polymer Electrolyte Enhances the Performance of High-Voltage Lithium Metal Batteries.

With the rapid evolution of electric vehicle technology, concerns regarding range anxiety and safety have become increasingly pronounced. Battery systems with high specific energy and enhanced security, featuring ternary cathodes paired with lithium (Li) metal anodes, are poised to emerge as next-generation electrochemical devices. However, the asymmetric configuration of the battery structure, characterized by the robust oxidative behavior of the ternary cathodes juxtaposed with the vigorous reductive activity of the Li metal anodes, imposes elevated requisites for the electrolytes. Herein, a well-designed gel polymer electrolyte with asymmetric structure was successfully prepared based on the Ritter reaction of cyanoethyl poly(vinyl alcohol) (PVA-CN) and cationic ring-opening polymerization of s-Trioxane. With the aid of the sieving effect of separator, the in situ asymmetric gel polymer electrolyte has good compatibility with both the high-voltage cathodes and Li anodes. The amide groups generated by PVA-CN after the Ritter reaction and additional cyano groups can tolerate high voltages up to 5.1 V, matching with ternary cathodes without any challenges. The functional amide and cyano groups participate in the formation of the cathode electrolyte interface and stabilize the cathode structure. Meanwhile, the in situ formed ether-based polyformaldehyde electrolyte is beneficial for promoting uniform Li deposition on anode surfaces. Li-Li symmetric cells demonstrate sustained stability over 2000 h of cycling at a current density of 1 mA cm-2 for 1 mAh cm-2. Furthermore, the capacity retention rate of Li(Ni0.6Mn0.2Co0.2)O2-Li cells with 0.5 C cycling after 300 cycles is 92.2%, demonstrating excellent cycle stability. The electrolyte preparation strategy provides a strategy for the progress of high-performance electrolytes and promotes the rapid development of high-energy-density Li metal batteries.

Opportunities to Enhance sCO2 Power Cycle Turbomachinery with Bearingless Motor/Generators

Thermal power cycles using sCO2 as a working fluid place extreme demands on their turbomachinery components and their electric motors/generators. In this paper, new system topologies for sCO2 turbomachinery are proposed which take advantage of “bearingless” electric machine technology to improve performance. Bearingless motors/generators are a new type of electric machine which integrate the functionality of active magnetic bearings into the existing hardware of an electric motor/generator. The existing electromagnetic surfaces and materials are reused to enable controllable production of radial forces on the machine shaft. This is envisioned to improve hermetic direct-drive turbomachinery systems by either augmenting existing bearings (i.e., bearing assist) or replacing existing bearings (i.e., bearing removal). The state-of-the-art technologies for several bearing types (gas foil bearings, externally pressurized porous (EPP) gas bearings, and active magnetic bearings) and electric machines are reviewed to motivate the introduction of bearingless technology. Two system designs using bearingless machines are proposed and compared against existing commercial solutions in terms of maximum shaft weight, number of passthroughs into the hermetic environment, cost, and complexity. A case-study bearingless motor/generator is assessed via simulations and a hardware prototype to investigate practical considerations for using bearingless technology in sCO2 turbomachinery. The proposed bearingless solutions have potential to enable a new generation of sCO2 turbomachinery with improved reliability, reduced complexity, and lower cost. This paper shows that by transforming the motor/generator already present in turbomachinery into a bearingless motor/generator, the technical challenges involved with sCO2 can be overcome without adding significant cost.

Projection of Electric Ships as Sustainable Transportation in the Capital City of Indonesia “Nusantara”

Abstract Nusantara is Indonesia’s new capital or knows as Ibu Kota Nusantara (IKN) for implementing the sustainable city concept. Waters separate the area around IKN with a total area of 68,188 ha. Therefore, people living in IKN, namely in Penajam and its surroundings, have become accustomed to using water transportation to travel between regions. Ship transportation that the community has often used has also been developed with electric ships to support sustainable cities and zero emissions at IKN. However, in implementing electric ships, problems arise, namely how to project the development of electric ship technology based on policy documents and development planning in the Nusantara Capital City. The objective to be achieved is to see the planning and policy document for developing environmentally friendly water transportation using electric power. The method used in this study is qualitative, with a synthesis approach. Data collection was carried out by document study from policies and regulations. The data was then analyzed descriptively to obtain important information about the problem. For the result, the projection of the of electric ships in IKN must be carefully planned so that it can be realized to support Sustainable City and zero emission in IKN later.

Perylene Bisimide-Functionalized Triphenylmethyl Radicals Showing High Stability and Reversible Electrochemical Redox Properties.

This study presents a series of triphenylmethyl monoradicals incorporating varying numbers of peripheral perylene bisimide (PBI) substituents (1PBI-TTM·, 2PBI-TTM· and 3PBI-TTM·). The incorporation of electron-withdrawing PBI substituents significantly enhances the stability of these carbon radicals, enabling them to display exceptional electrochemical redox reversibility. Notably, the electronic interplay between the PBI substituents and the central triphenylmethyl core facilitates unique and reversible multi-step redox reactions. Among the reported redicals, the tris-PBI functionalized radical (3PBI-TTM·) demonstrates the remarkable ability to accommodate up to seven electrons under negative potentials, forming high valence anions. This research pioneers the development of highly stable carbon radicals with superior electrochemical oxidation-reduction processes, presenting promising avenues for the advancement of electric energy storage technologies.

Preface

International Conference on Hydrodynamics, Energy and Electric Power System (HEEPS) is an annually held conference, it aims to provide a forum for participants to exchange their experiences, share research results in all aspects about Hydrodynamics, Energy and Electric Power System and discuss the encountered practical challenges and the adopted solutions. The 2024 8th International Conference on Hydrodynamics, Energy and Electric Power System (HEEPS 2024) was held in Beijing, China from June 28th to 30th, 2024. This esteemed conference, as the eighth in its series, continues to serve as a premier platform for researchers, scholars, and industry professionals to converge, share insights, and collaborate on the latest advancements in hydrodynamics, water resources and hydropower engineering, energy systems, and electric power technologies. HEEPS 2024 was organized with the aim of fostering interdisciplinary dialogue and innovation within the rapidly evolving fields of fluid mechanics, energy systems, and power engineering. Building upon the success of the previous seven editions, this conference attracted a diverse and vibrant community of participants from around the world. The event was hosted with the support of esteemed institutions such as the University of Chinese Academy of Sciences and Universiti Putra Malaysia, further enhancing its international reach and impact. HEEPS 2024 was an outstanding three-day conference and a reference that attracted many remarkable keynote speakers, including: Professor Jizhong Zhu (South China University of Technology, China), Professor Ishak Bin Aris (Universiti Putra Malaysia, Malaysia), Professor Lin Chen (Chinese Academy of Sciences, China), Associate Professor Sohrab Mirsaeidi (Beijing Jiaotong University, China), as well as Assistant Professor Jianxiao Wang (Peking University, China). The program kicked off with a series of keynote lectures delivered by renowned experts in their respective fields, setting the tone for an intellectually stimulating conference. These presentations covered a broad spectrum of topics, ranging from fundamental research in hydrodynamics and fluid mechanics to the latest developments in energy systems and power grid technologies. Besides, during all parts of the conference, the attendees actively interacted with the speakers and each other on specific topics. The conference’s Proceedings of HEEPS 2024 contains the papers accepted and presented at this great conference. All these contributions were carefully reviewed by program committee members and took into consideration the breadth and depth of the research topics that fall into HEEPS scope. On behalf of the conference organizers, we would like to take this opportunity to express our sincere thanks to all the editors and reviewers for their tremendous efforts and dedication to the conference. We also wish to thank all the authors and speakers for their great contributions to this conference and the conference’s Proceedings. And we believe that with such earnest support and contributions, the future HEEPS conferences will also scale new heights. The Committee of HEEPS 2024 List of Committee Member are available in this pdf.

Electrifying the bus network with trolleybus: Analyzing the in motion charging technology

Currently, electric buses are becoming more and more popular, and their number in operation is increasing. The range of electric buses is also increasing and solutions that seem to be working almost without fixed infrastructure are being promised. However, this requires the use of high-capacity batteries, which increases the weight and price of the vehicle and causes high costs of battery replacement during operation. Moreover, if we take into account the growing demand for batteries, limited raw material resources, and the environmental impact of the battery production process, the optimization of battery capacity in vehicles may turn out to be a key issue. In this light, trolleybus becomes a sustainable and economically efficient bus electrification technology, if considered in an international scope and a medium- to long-term approach. The article provides a comprehensive study of challenges and potential solutions related to electric buses, which covers the theoretical analysis, technical aspects and practical applications, thus making a valuable resource for readers interested in sustainable urban transport systems. It presents the trolleybus technology, especially with modern solutions, as a sustainable and economically efficient tool for bus electrification. The article shows that the In Motion Charging (IMC) system reduces the need for high-capacity batteries under 100 kWh, which allows to extend their service life up to 15 years and, consequently, to reduce the number of buses needed for operation. The research was based on real measurement data from the transport system in Gdynia (Poland).

Microwave Chemistry as a Candidate of Electrification Technology toward Carbon Neutrality—Microwave Magnesium Smelting as an Example

Microwave Chemistry as a Candidate of Electrification Technology toward Carbon Neutrality—Microwave Magnesium Smelting as an Example

Opportunities and challenges for direct electrification of chemical processes with protonic ceramic membrane reactors

Abstract The necessity of developing sustainable energy storage and process electrification technologies has built an unprecedented momentum for protonic ceramic membrane reactors (PCMRs). PCMRs are practically electrolytic cells (or even fuel cells in case of cogeneration) that extend beyond the classical approach of electrolysis towards producing a variety of value-added chemicals or fuels. The use of a ceramic electrolyte membrane to electrochemically supply or remove hydrogen offers unique advantages, such as process intensification, cogeneration of chemicals and electricity, as well as the shift of the chemical equilibrium to the desired products. During the last few years, rapid progress has not only been made in the cell components, but also for upscaling, which reveals their high potential in terms of efficiency and flexibility. Herein, we discuss recent innovations and breakthroughs in the PCMR concepts and components for different processes, while we attempt to identify challenges that may hinder their wide deployment. Closer to commercialization is the production of pressurized hydrogen from sustainable sources, i.e. biogas and ammonia, while significant advancements have been made in reversible H2O electrolysis systems. CO2/H2O co-electrolysis, hydrocarbon conversion and ammonia synthesis have been also successfully demonstrated, albeit with different obstacles related to the product selectivity and stability of the cell reactors. We conclude that future projects should target beyond the experimental discovery of materials, such as, multiscale modeling that would aid optimization of the involved surfaces, interfaces, and the operating parameters towards enhancing the viability of electrosynthesis in PCMRs.

Power Distribution Transformer Maintenance Skills Required byElectrical Engineering Technology Students ofPolytechnics inNorth-East Nigeria

Electric power distribution industry in North-East, Nigeria is faced with inadequate number of power transformer maintenance personnel which has led to numerous abandonment of broken down power transformers. Transformer faults have been blamed for many power outages of long duration in many towns and communities in North-East, Nigeria.It is against this backdrop that thisstudy determined the power distribution transformer maintenance skills required by Electrical Engineering Technology students of polytechnics in North-East Nigeria. Three research questions and three hypotheses guided the study which employed a descriptive survey research design. The population of the study was 144 comprising of 135 Electrical Engineering Technology Lecturers, 3 Power Transformer Maintenance Technicians and 6 Electric Power Distribution Company-Based Supervisors. The entire population was used hence, there was no sampling. The instrument used for data collection was a structured questionnaire titled: Power Distribution Transformer Maintenance Skills Required Questionnaire (PDTMSRQ) developed by the researchers. The instrument was validated by three experts and a reliability of 0.74 was obtained using Cronbach Alpha reliability method. Mean statistic was used to answer the research questions while ANOVA was used to test the two null hypotheses of the study at 0.05 level of significance. The findings of the study revealed that the Electrical Engineering Technology students of polytechnics in North-East Nigeria required preventive, predictive and corrective maintenance skills. The study recommended the following: Lecturers should encourage the students’ skill acquisition process by exposing them to various maintenance activities in order for them to imbibe the different methods of power transformer maintenance; Students should be trained to recognize sounds and sights of faulty equipment in order to predict the parts or components that needed replacement or repairs.

Feasibility and application of novel electrical curing method for constant-temperature hardening of concrete at cold regions

To explore the feasibility and strategies of applying electric curing technology to reinforced concrete components, this study introduces a method of electric curing for concrete constant temperature hardening (EC-CCTH). Concrete specimens were placed in an environment with a temperature of −10 °C, and an EC-CCTH system was used to maintain the internal temperature of the specimens at 20 °C. The analysis focused on the specimens' strength, temperature, microstructure, and energy consumption. Under winter conditions with ambient temperatures ranging from 1 °C to 7 °C, EC-CCTH was applied to concrete slabs, and their strength and temperature were monitored. Additionally, numerical simulations were conducted to further examine the current density and temperature distributions within the slabs. The results showed that the 28-day strength values of electrically cured specimens were comparable to those of standard-cured specimens. The hydration process and pore structure of the concrete specimens remained unaffected by the application of alternating current. Although the presence of steel bars led to an uneven distribution of current density and non-uniform heat generation within the concrete, this was mitigated by thermal conduction effects. Due to the constant temperature effect of the electric field, the concrete slab reached a strength of 13.9 MPa at 3 days, indicating the practical feasibility of EC-CCTH in engineering. Furthermore, the energy consumption for EC-CCTH of the slab was only 20.1 kW h, highlighting its effectiveness in reducing energy consumption and carbon emissions.

Degradation Mechanism and Online Electrical Monitoring Techniques of Stator Winding Insulation in Inverter-Fed Machines: A Review

Inverter-fed machines are widely used in electric vehicle drive systems and have shown a trend toward high voltage and frequency in recent years. They are subjected to multiple types of stress during operation, causing potential short-circuit fault damage to the stator winding insulation. Online condition monitoring of the insulation before or in the early stage of the short circuit fault can effectively reduce maintenance costs and ensure its health. This paper reviews and summarizes the deterioration mechanism and the recent online electrical monitoring techniques. First, four types of failure stress and each type’s failure factors and mechanisms are analyzed. The coupling effect and overall process of multi-physical fields on stator insulation failure are considered. Secondly, the latest online electrical monitoring technologies are summarized. Each technique’s principles, methods, advantages, and disadvantages are analyzed. Finally, existing problems and possible directions for improvement in current research are discussed, focusing on their feasibility and accuracy in practical applications.

Investigating the potential advancements for electric vehicle charging technologies through various converters topology

Investigating the potential advancements for electric vehicle charging technologies through various converters topology

Study on the Model of Integrated Education of Vocational Electrical Automation Technology “Post-course Competition Certificate” Under the Integration of School and Enterprise

Based on the perspective of university-enterprise integration, this paper first analyzes the post ability demand of electrical automation technology and reconstructs the course system and multi-dimensional evaluation system of the deep integration of post, competition, certificate and creation course. Then, according to the curriculum settings, from the aspects of teaching resource allocation, school-enterprise cooperation mechanism reform, teachers, teaching methods, and teaching materials reform, enable the implementation of “post-course competition certificate creation” integrated education mode, effectively improve the quality of talent training and better serve the new quality productivity.

Analysis of rock-breaking mechanisms of high-voltage pulsed electric electrode bits

High-voltage pulsed electric rock-breaking technology is an innovative, green, and efficient method with substantial potential in the field of rock fragmentation. The efficiency of this technology is primarily determined by the design of the electrode bit. To investigate the impact of electrode bit design on rock fragmentation, this study developed a three-dimensional electro-rock breaking model based on the coupling of multiple fields: current field, electrostatic field, breakdown field, heat transfer field, and solid mechanics field. Using this comprehensive three-dimensional model, we conducted dynamic electrical breakdown simulations of granite, incorporating five different electrode bit structures and six degrees of rock heterogeneity. The simulation results elucidate the effects of pulsed peak voltage, granite heterogeneity H , and electrode bit structure on the efficiency of high-voltage pulsed electric rock breaking. To validate the simulation results, laboratory experiments on electro-rock breaking were performed. The experimental findings indicate that the conical electrode bit exhibited the highest rock-breaking efficiency, while the pentagonal prism-shaped electrode bit showed the poorest performance. The tip of prismatic electrodes generates a tip discharge effect; for the triangular prism, this effect often results in irregular rock fragmentation, which is detrimental to drilling efficiency. These results highlight the significant influence of electrode shape on rocks’ electrical breakdown and fragmentation. This study provides valuable insights into the engineering application of high-voltage pulsed electric rock-breaking technology.

All-fiber tunable mode converter for a mini-two-arm Mach-Zehnder interferometer.

In this Letter, an all-fiber tunable mode converter for a mini-two-arm Mach-Zehnder interferometer (MTA-MZI) is proposed and realized for the first time to our knowledge. Employing an electric arc discharge technology, we couple a multi-mode fiber (MMF) and a single-mode fiber (SMF), resulting in an MZI characterized by centimeter-scale arms. The varied sensitivity of fiber modes to curvature makes the high-order modes of the MMF more prone to leakage when subjected to bending, leading to alterations in the output interference fringe pattern of the MZI. Through continuous monitoring of the interference fringes of the MZI, we effectively detect the mode properties within the MZI in real time. In addition, a verification experiment is conducted by introducing a peanut structure to excite further higher-order modes of light to enter the MZI in advance. Upon modifying the curvature of the MZI, these excited higher-order modes leak, causing the interference fringe pattern to revert to its initial state without a peanut structure. This experimental validation highlights the potential employment of the MTA-MZI as an all-fiber mode converter and paves the way for optical field mode conversion within an all-fiber framework.

The technological transformation of the Russian energy sector forced by carbon regulation

RELEVANCE of the study lies in the assessment of the impact that various carbon regulation instruments stimulating the achievement of national climate goals have on the development scale of different electricity and heat production technologies in Russia.THE PURPOSE. To consider the change in the optimal technological structure of the electric power industry and district heating in Russia by 2050 assuming the introduction of various carbon regulation instruments in 2030.METHODS. We used the developed at ERI RAS system technological model EPOS for the optimization of the energy technology structure in the Russian energy sector according to the criterion of the minimum total discounted costs for energy supply to the economy until 2050.RESULTS. The article provides an analysis of the scale of changes in installed capacity and electricity production of various types of power plants in the UES of Russia, as well as changes in heat production of different heat supply sources by 2050 for 16 carbon regulation options and business-as-usual scenario. Also it describes the optimal technological structure in the electric power industry and district heating under the conditions of certain administrative, fiscal and economic instruments of climate policy. Carbon regulation options based on the corresponding increases in the installed capacity of power plants in the UES of Russia by 2050 are compared.CONCLUSION. Decarbonization of the electric power industry in Russia will mainly occur by expansion of nuclear energy, heat production – by deployment of electric boilers, taking into account current forecasts of scientific and technological progress. At the same time, for carbon regulation options leading to a greenhouse gas emissions reduction by 30% relative to 2019 level, nuclear power plants could become the new dominant technology in the structure of electricity production instead of gas thermal power plants. The total increase in installed capacity of power plants in the UES of Russia by 2050 may differ by almost seven times for various carbon regulation options. Among the climate policy options considered, emission quotation and carbon taxes have the strongest impact on the technological structure of the electric power industry and district heating in Russia.