Review
Engineering, Multidisciplinary
Muhammad Rafiq, Muhammad Shafique, Anam Azam, Muhammad Ateeq
Summary: Research and applications of NFs as heat transfer fluids are rapidly growing, with a focus on preparing NFs by suspending solid nanoparticles in conventional working liquids. The impact of various factors on the thermophysical properties of NFs remains controversial, and proper characterization and material selection for NFs are crucial for improving heat transfer efficiency.
AIN SHAMS ENGINEERING JOURNAL
(2021)
Article
Engineering, Environmental
Hou-Qing Wang, Jing-Wen Wang, Xin-Zhu Wang, Xin-Hua Gao, Guo-Chao Zhuang, Jian-Bao Yang, Hua Ren
Summary: 2D/2D heterostructures of 2D MoS2 grown on the surface of 2D transition metal carbide Ti3C2 MXene (MoS2@MXene) were successfully synthesized through hydrothermal reaction. MoS2@MXene was incorporated into PVDF to form the MoS2@MXene/PVDF composites, which exhibited excellent flexibility and high energy storage performance.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Mississippi M. Bhunia, Karamjyoti Panigrahi, Chandra B. Naskar, Souvik Bhattacharjee, Kalyan K. Chattopadhyay, Paramita Chattopadhyay
Summary: Rutile TiO2 nanoparticles with high dielectric constant are a preferred nanofiller for transformer oil nanofluids, enhancing breakdown voltage and thermal conductivity. The use of TiO2 also reduces acidity and viscosity in nanofluids due to its specific properties, making it a promising candidate for efficient nanofluid development.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Engineering, Electrical & Electronic
Amr M. Abd-Elhady, Ahmed A. Abdul-Aleem, Mohamed A. Izzularab
Summary: This study evaluated the electrical properties of nano-filled oil-paper insulation and found that the filler types and permittivity significantly impact the breakdown strength, volume resistivity, and dielectric response of oil-paper composites. Nano-fillers with higher permittivity were shown to provide greater improvements in breakdown strength compared to those with lower permittivity. The results were comprehensively interpreted with regards to breakdown strength, volume resistivity, and dielectric response.
IET SCIENCE MEASUREMENT & TECHNOLOGY
(2021)
Article
Polymer Science
Liang Cao, Lisheng Zhong, Yinge Li, Jinghui Gao, George Chen
Summary: The study revealed that the increase in crosslinking degree led to enhanced DC breakdown strength but decreased crystallinity, reduced elastic modulus, and lower loss tangent peak temperature for XLPE-PS composites.
Article
Chemistry, Multidisciplinary
Junlei Qi, Minhao Zhang, Yiying Chen, Zixi Luo, Peiyao Zhao, Hang Su, Jian Wang, Hongye Wang, Letao Yang, Hao Pan, Shun Lan, Zhong-Hui Shen, Di Yi, Yuan-Hua Lin
Summary: The HCE design of BaTiO3-BiFeO3-CaTiO3 material demonstrates ultrahigh energy density and offers a route for improving the compactness and high performance of dielectric devices.
CELL REPORTS PHYSICAL SCIENCE
(2022)
Article
Computer Science, Information Systems
Mohamed Badawi, Shimaa A. Ibrahim, Diaa-Eldin A. Mansour, Adel A. El-Faraskoury, Sayed A. Ward, Karar Mahmoud, Matti Lehtonen, Mohamed M. F. Darwish
Summary: This paper presents a comprehensive maintenance method for power transformers, aiming to accurately diagnose transformer faults. It proposes an integrated dissolved gas analysis (DGA) method that improves the overall accuracy by 93.6% compared to existing techniques. The paper also evaluates the health index of new and aged transformers by analyzing breakdown voltage, DGA, moisture content, and acidity of the transformer oil.
Article
Engineering, Electrical & Electronic
Amr M. Abd-Elhady, Alyaa A. Nassar, Mohamed A. Izzularab, Mohamed E. Ibrahim
Summary: The main focus of this study is to investigate the thermal aging of oil filled transformers, with particular emphasis on the insulation system. The results show that the performance of the oil/paper insulation system is significantly affected by factors such as epoxy coating and nanofillers.
ELECTRIC POWER SYSTEMS RESEARCH
(2022)
Article
Engineering, Multidisciplinary
M. H. A. Hamid, M. T. Ishak, N. S. Suhaimi, J. Adnan, N. Hashim, M. Ariffin, N. I. A. Katim, Rahisham Abd Rahman
Summary: This paper investigates the dielectric properties and AC breakdown voltage behavior of Palm Oil (PO) and Rice Bran Oil (RBO). It is found that RBO has better insulating oil capability than PO, and PO has advantages in terms of stress distribution. RBO has the highest breakdown voltage, followed by PO, while MO shows the lowest breakdown voltage.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Crystallography
Bin Cao, Ji-Wei Dong, Ming-He Chi
Summary: Water impurities in transformer oil play a key role in accelerating thermal diffusion of water molecules and introducing conductive electron states, ultimately leading to electrical breakdown. Increased aging acid concentration significantly promotes thermal diffusion of water impurities, impacting the dielectric strength of insulating oil.
Article
Materials Science, Multidisciplinary
Mengjia Feng, Yu Feng, Changhai Zhang, Tiandong Zhang, Xu Tong, Qiang Gao, Qingguo Chen, Qingguo Chi
Summary: Optimizing the high-temperature energy storage characteristics of energy storage dielectrics is important for the development of pulsed power devices and power control systems. Selecting a polymer with a higher glass transition temperature (T-g) and combining it with other polymers can improve the high-temperature breakdown strength and energy storage efficiency. The novel high-T-g polymer fiber-reinforced microstructure, with polyimide fibers distributed in the composite dielectric, shows excellent high-temperature energy storage properties.
ENERGY & ENVIRONMENTAL MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Lijun Zhou, Jun Zhang, Zhixin Li, Rongting Wen, Dongyang Wang, Jiekang Wu, Huiling Tang
Summary: Frequency domain dielectric spectroscopy (FDS) is used to reflect the aging status of silicone oil-immersed insulation paper. In this study, an evaluation method was developed by analyzing the aging kinetic model and FDS results. The method includes separating different polarization losses and conductivity loss from FDS results, modifying the zero order aging dynamic model, and proposing an evaluation method for the degree of polymerisation (DP) of silicone oil-immersed paper. Experiments were conducted to verify the proposed method, and the results showed its effectiveness.
Article
Chemistry, Physical
Zaid B. Siddique, Soumen Basu, Prasenjit Basak
Summary: This paper focuses on studying the dielectric behavior of a mixture of natural ester oil and mineral oil blend dispersed with TiO2 and ZnO nanoparticles. The results show an overall enhancement in the dielectric properties of nanofluids, with improved breakdown voltage compared to pure mineral oil, pure ester oil, and the oil-blend. These nanofluids can be used as insulating oils in transformers, offering better cooling performance as well.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Physics, Applied
Meng Xiao, Mengdie Zhang, Boxue Du, Zhaoyu Ran, Haoliang Liu, Yawei Qin
Summary: This paper proposes a method to improve the breakdown strength of polypropylene (PP) film at high temperatures by introducing long-chain branches (LCBs). The results show that LCBs increase the number of spherulites and refine the grains, reducing the weak areas in the films.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Zhong-Hui Shen, Zhi-Wei Bao, Xiao-Xing Cheng, Bao-Wen Li, Han-Xing Liu, Yang Shen, Long-Qing Chen, Xiao-Guang Li, Ce-Wen Nan
Summary: This study developed an integrated phase-field model to investigate the performance of polymer nanocomposites, revealing that parallel perovskite nanosheets can significantly improve breakdown strength, leading to the preparation of polymer nanocomposites with excellent energy storage capabilities.
NPJ COMPUTATIONAL MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Wandry R. Faria, Gregorio Munoz-Delgado, Javier Contreras, Benvindo R. Pereira Jr
Summary: This paper proposes a new bilevel mathematical model for competitive electricity markets, taking into account the participation of distribution systems operators. A new pricing method is introduced as an alternative to the inaccessible dual variables of the transmission system.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Chao Zhang, Liwei Zhang, Dong Wang, Kaiyuan Lu
Summary: The load disturbance rejection ability of electrical machine systems is crucial in many applications. Existing studies mainly focus on improving disturbance observers, but the speed response control during the transient also plays a significant role. This paper proposes a sliding mode disturbance observer-based load disturbance rejection control with an adaptive filter and a Smith predictor-based speed filter delay compensator to enhance the transient speed response.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Arif Hussain, Arif Mehdi, Chul-Hwan Kim
Summary: The proposed scheme in this research paper is a communication-less islanding detection system based on recurrent neural network (RNN) for hybrid distributed generator (DG) systems. The scheme demonstrates good performance in feature extraction, feature selection, and islanding detection, and it also performs effectively in noisy environments.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Zonghui Sun, Xizheng Guo, Shinan Wang, Xiaojie You
Summary: This paper presents a status pre-matching method (SPM) that eliminates the iterative calculations for resistance switch model, and simulates all operation modes of PECs through a more convenient approach. Furthermore, a FPGA implementation scheme is proposed to fully utilize the multiplier units of FPGA.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Rui Zhou, Shuheng Chen, Yang Han, Qunying Liu, Zhe Chen, Weihao Hu
Summary: In power system scheduling with variable renewable energy sources, considering both spatial and temporal correlations is a challenging task due to the complex intertwining of spatiotemporal characteristics and computational complexity caused by high dimensionality. This paper proposes a novel probabilistic spatiotemporal scenario generation (PSTSG) method that generates probabilistic scenarios accounting for spatial and temporal correlations simultaneously. The method incorporates Latin hypercube sampling, copula-importance sampling theory, and probability-based scenario reduction technique to efficiently capture the spatial and temporal correlation in the dynamic optimal power flow problem. Numerical simulations demonstrate the superiority of the proposed approach in terms of computational efficiency and accuracy compared to existing methods.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Juan Manuel Mauricio, J. Carlos Olives-Camps, Jose Maria Maza-Ortega, Antonio Gomez-Exposito
Summary: This paper proposes a simplified thermal model of VSC, which can produce accurate results at a low computational cost. The model consists of a simple first-order thermal dynamics system and two quadratic equations to model power losses. A methodology is also provided to derive the model parameters from manufacturer data.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Jae-Kyeong Kim, Kyeon Hur
Summary: This paper investigates the relationship between the accuracy of finite difference-based trajectory sensitivity (FDTS) analysis and the perturbation size in non-smooth systems. The study reveals that the approximation accuracy is significantly influenced by the perturbation size, and linear approximation is the most suitable method for practical applications.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Yuan Si, Amjad Anvari-Moghaddam
Summary: This paper investigates the impact of geomagnetic disturbances on small signal stability in power systems and proposes the installation of blocking devices to mitigate the negative effects. Quantitative evaluation reveals that intense geomagnetic disturbances significantly increase the risk of small signal instability. Optimal placement of blocking devices based on sensitivity scenarios results in a significant reduction in the risk index compared to constant and varying induced geoelectric fields scenarios.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Xuejian Zhang, Wenxin Kong, Nian Yu, Huang Chen, Tianyang Li, Enci Wang
Summary: The intensity estimation of geomagnetically induced currents (GICs) varies depending on the method used. The estimation using field magnetotelluric (MT) data provides the highest accuracy, followed by the estimation using 3D conductivity models and the estimation using a 1D conductivity model. The GICs in the North China 1000-kV power grid have reached a very high-risk level, with C3 and C4 having a significant impact on the geoelectric field and GICs.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Yue Pan, Shunjiang Lin, Weikun Liang, Xiangyong Feng, Xuan Sheng, Mingbo Liu
Summary: This paper introduces the concept and model of offshore-onshore regional integrated energy system, and proposes a stochastic optimal dispatch model and an improved state-space approximate dynamic programming algorithm to solve the model. The case study demonstrates the effectiveness and high efficiency of the proposed method in improving economic and environmental benefits.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Mohammad Eydi, Reza Ghazi, Majid Oloomi Buygi
Summary: Proportional current sharing, voltage restoration, and SOCs balancing in DC microgrid control algorithms are the leading challenges. This paper proposes a novel communication-less control method using a capacitor and a DC/DC converter to stabilize the system and restore the DC bus voltage. The method includes injecting an AC signal into the DC bus, setting the current of energy storage units based on frequency and SOC, and incorporating droop control for system stability. Stability analysis and simulation results validate the effectiveness of the proposed method.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Xiangjian Meng, Xinyu Shi, Weiqi Wang, Yumin Zhang, Feng Gao
Summary: With the increasing penetration of photovoltaic power generation, regional power forecasting becomes critical for stable and economical operation of power systems. This paper proposes a minute-level regional PV power forecasting scheme using selected reference PV plants. The challenges include the lack of complete historical power data and the heavy computation burden. The proposed method incorporates a novel reference PV plant selection method and a flexible approach to decrease the accumulated error of rolling forecasting.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Huabo Shi, Yuhong Wang, Xinwei Sun, Gang Chen, Lijie Ding, Pengyu Pan, Qi Zeng
Summary: This article investigates the dynamic stability characteristics of the full size converter variable speed pumped storage unit and proposes improvements for the control strategy. The research is important for ensuring the safe and efficient operation of the unit.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Firmansyah Nur Budiman, Makbul A. M. Ramli, Houssem R. E. H. Bouchekara, Ahmad H. Milyani
Summary: This paper proposes an optimal harmonic power flow framework for the daily scheduling of a grid-connected microgrid, which addresses power quality issues and ensures effective control through demand side management.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Engineering, Electrical & Electronic
Cong Zeng, Ziyu Chen, Jizhong Zhu, Fellew Ieee
Summary: This paper introduces a distributed solution method for the multi-objective OPF problem, using a coevolutionary multi-objective evolutionary algorithm and the idea of decomposition. The problem is alleviated by decomposing decision variables and objective functions, and a new distributed fitness evaluation method is proposed. The experimental results demonstrate the effectiveness of the method and its excellence in large-scale systems.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)