IEEJ Transactions on Electrical and Electronic Engineering最新文献

{"title":"Intelligent Prediction of Dielectric Strength for Long Air Gaps at High Altitudes Based on Regularization-Logistic Regression","authors":"Zhibin Qiu,&nbsp;Wenhao Chen,&nbsp;Yu Song,&nbsp;Ting Peng,&nbsp;Chen Liu","doi":"10.1002/tee.70051","DOIUrl":"https://doi.org/10.1002/tee.70051","url":null,"abstract":"<p>Air discharge originates from the interaction between electric field (EF) and the meteorological environment, and the dielectric strength of a long air gap is affected by both EF distribution and atmospheric parameters. A regularization-logistic regression (R-LR) model is proposed for the accurate calculation of long air gap discharge voltage at high altitudes. Using 4 meteorological features and 9 EF features as inputs for the R-LR model, the R-LR model was trained using discharge test data from rod-plane air gaps at altitudes of 55–4300 m. The trained model was used to predict the dielectric strength of rod-plane air gaps at an altitude of 5000 m. The prediction results of the R-LR model were compared with those of random forest (RF), support vector classifier (SVC) and <i>k</i>-nearest neighbor (KNN) models. The results showed that the accuracy and generalization of the R-LR model were better than those of the other models. The MAPE of the R-LR model on the test set was 1.32%. The model was validated by using the rod-plane air gap discharge test data under different meteorological environments in a plain area. The predicted discharge voltage values were basically consistent with the test values, further demonstrating the effectiveness and generalizability of the model. This study can offer a reference for predicting the dielectric strength of air gaps under different meteorological environments in high altitude areas. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 8","pages":"1148-1156"},"PeriodicalIF":1.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144574139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hierarchical Optimization Combining Parameter and Topology for Outer Rotor in-Wheel Motors","authors":"Kehan Yan,&nbsp;Zunyan Hu,&nbsp;Jianqiu Li,&nbsp;Liangfei Xu,&nbsp;Minggao Ouyang","doi":"10.1002/tee.70055","DOIUrl":"https://doi.org/10.1002/tee.70055","url":null,"abstract":"<p>In-wheel motor (IWM) optimization is critical for its vehicle integration. However, standard algorithms are frequently ineffective when applied to the complex IWM optimization problem, resulting in suboptimal performance and excessive computational costs. This problem arises from the diverse and conflicting objectives, namely peak torque, torque ripple, efficiency, and weight. Thus, this paper introduces a hierarchical optimization method that integrates parameter and topology optimization according to different objectives sequentially. The upper layer employed a computationally fast surrogate model to explore the parameter spaces extensively and select the working point for torque ripple reduction. Then, the lower layer utilizes the best parameter optimization results as constraints, enabling further refinement of the permanent magnet (PM) topology via accurate finite element analysis (FEA). As a result, a radial outer rotor IWM was optimized using this method. Convergence and prototype analyses demonstrate the reliability of the hierarchical optimization with a 10.6% and 1.6% increase in peak torque and efficiency, respectively, and a 43.2% reduction in the torque ripple rate compared with a traditionally engineered counterpart. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 8","pages":"1282-1293"},"PeriodicalIF":1.0,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144573708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing Cable Replacement Schedules in Power Grids: A Data-Driven Approach with Machine Learning and Power Flow Analysis","authors":"Junhyun Lee,&nbsp;Junseon Park,&nbsp;Hyeongon Park","doi":"10.1002/tee.70056","DOIUrl":"https://doi.org/10.1002/tee.70056","url":null,"abstract":"<p>Ensuring stable power supply demands maintaining power facilities in a reliable operating condition. Power facilities are categorized into those that can be monitored in real time and those that cannot. Facilities that cannot be monitored, such as cables, are often replaced when they are old or replaced in batches. This replacement method overlooks the actual condition and failure impact of these facilities, potentially resulting in economic losses. In this study, we propose a method for optimizing the cable replacement schedules. This method takes into account the Health Index level and the importance in power grid operation. Leveraging machine learning with a dataset of cables, we predicted the Health Index for each cable. Then, we assessed the importance of each cable by calculating load shedding scenarios through power flow analysis, should a cable fail. Finally, the prioritization for cable replacement was determined based on the potential loss caused by cable failure. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 9","pages":"1497-1502"},"PeriodicalIF":1.1,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Mixed Integer-Linear Programming Model for Solving the Hydroelectric Unit Maintenance Scheduling Problem","authors":"Yuehao Tang","doi":"10.1002/tee.70050","DOIUrl":"https://doi.org/10.1002/tee.70050","url":null,"abstract":"<p>This paper presents an optimization modeling approach utilizing Mixed Integer Linear Programming (MILP) techniques to address the hydroelectric unit maintenance scheduling problem for British Columbia Hydro and Power Authority (BC Hydro) systems. The research leverages specialized linear formulations and algorithms to solve the combinatorial maintenance problem in large-scale hydroelectric systems. The primary objective is to determine the optimal timing and sequencing for each unit outage within the system, ensuring system productivity, reliability, and operability. The proposed method involves a detailed MILP formulation that considers various constraints. A novel ‘maintenance shape’ algorithm is designed to handle the nonlinearity arising from the maintenance continuity preference, ensuring that all units' maintenance activities within each plant are arranged sequentially without breaks. Results from the case study illustrate the systematic effects of unit maintenance on BC Hydro's competitiveness in the electricity market. The model can be extended to include more plants and reservoirs, providing a valuable tool for BC Hydro and similar utilities in strategically managing their maintenance operations. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 8","pages":"1165-1175"},"PeriodicalIF":1.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144573633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constrained State Estimation with Probabilistic Error Model for Underdetermined Systems Such as Distribution Network","authors":"Masatoshi Kumagai,&nbsp;Masahiro Watanabe","doi":"10.1002/tee.70054","DOIUrl":"https://doi.org/10.1002/tee.70054","url":null,"abstract":"<p>Constrained state estimation (CSE) clarifies the interval of the feeder voltage profile of an unobservable distribution network containing fewer telemetric sensors than state variables to be estimated. By using the given information about the power flow equations and network operating ranges such as maximum load and photovoltaic generator ratings, CSE provides the estimation interval that minimizes the square error against the partial telemetric measurements while satisfying the network operating ranges. We also developed a probabilistic model of the estimation error outside the estimation interval characteristic of the CSE algorithm. The probabilistic error model is derived by superposition of the error distribution around the arbitrary estimation within the estimation interval. The validity of the probabilistic error model was confirmed by a case study simulation on a benchmark network, in which the model-based probabilistic error distribution well explained the simulation-based estimation errors. This result is necessary to understand the estimation accuracy of CSE for the voltage control application of the distribution network. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 8","pages":"1186-1194"},"PeriodicalIF":1.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144573639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Vision-Based Technique for Ice-Coating Shape Measurement of Transmission Lines Conductor","authors":"Ye Zhang,&nbsp;Luyao Wang,&nbsp;Pengchao Zhai,&nbsp;Long Zhao","doi":"10.1002/tee.70052","DOIUrl":"https://doi.org/10.1002/tee.70052","url":null,"abstract":"<p>Icing of overhead transmission lines can affect the safe operation of the power distribution and transmission grid due to the additional weight load of the accumulated ice-coating on transmission line conductors. Analyzing the shape of ice accumulation on transmission line conductors helps promote the calculation of ice thickness and weight. In this paper, we present a system for analyzing the shape of ice accumulation based on two digital cameras and an offline processing algorithm. The two cameras separately acquire an image sequence of the iced conductor from the top view and the front view. Then, an image processing algorithm extracts the conductor contour and measures both the diameters of the iced conductor images captured by the two cameras at the same point. An irregular-shape ice coating accumulation model is established and used to describe the cross-sectional ice coating shape of the accumulated ice on the conductor. Finally, a mathematical model for the ice coating weight is established. The proposed system was tested in laboratory experiments using two digital cameras with good low-temperature resistance. The experimental analysis results show that the average error ratio of the proposed irregular shape ice accumulation model in terms of area and thickness fitting are 0.0398 and 0.0612, respectively. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 8","pages":"1176-1185"},"PeriodicalIF":1.0,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144574273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Specialized Variational Autoencoder for Cost-Efficient Pedestrian Trajectory Prediction","authors":"Dongchen Li,&nbsp;Zhimao Lin,&nbsp;Jinglu Hu","doi":"10.1002/tee.70053","DOIUrl":"https://doi.org/10.1002/tee.70053","url":null,"abstract":"<p>The prediction of pedestrian trajectories represents a crucial and widely discussed topic in the field of AI-driven traffic scenarios. The prediction of pedestrian trajectories is constrained by two factors. First, pedestrians do not have the same traffic rule constraints as vehicles. Second, the computational power of in-vehicle systems is limited. This renders the application of traditional methods challenging. Previous methods have been observed to utilize redundant information, which can result in feature imbalance and the potential for model overfitting. In light of these limitations, we propose a lightweight conditional variational autoencoder model with post-process (L-CVAE-P) for pedestrian prediction scenarios. The L-CVAE-P focuses on the efficient interaction of multidimensional features to achieve a comprehensive enhancement of the model for real-world use. The model is tested on two public datasets and achieved state-of-the-art performance, while maintaining efficiency. The experimental results demonstrate that our work has developed and optimized a pedestrian trajectory prediction model for practical applications. © 2025 The Author(s). <i>IEEJ Transactions on Electrical and Electronic Engineering</i> published by Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 8","pages":"1240-1249"},"PeriodicalIF":1.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/tee.70053","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144574284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Self-Switching Topology for Three Coils Structure Wireless Power Transfer System with Constant Current and Constant Voltage","authors":"Pengfei Gao,&nbsp;Yafang Shi,&nbsp;Fangyuan He,&nbsp;Jie Wu,&nbsp;Yafei Chen,&nbsp;Yiming Ji","doi":"10.1002/tee.70016","DOIUrl":"https://doi.org/10.1002/tee.70016","url":null,"abstract":"<p>With the development of the transportation industry, the demand for road health conditions is also increasing. Therefore, a significant number of road health monitoring sensors need to be deployed. However, charging sensors buried in the ground is a challenge. A self-switching topology suitable for wireless power transmission (WPT) systems with a constant current (CC) and constant voltage (CV) three-coil structure is proposed to solve the problems of overcharging or undercharging of wired power sources and batteries. The system has established a theoretical model based on the LCC/S-S-S circuit theory and conducted data analysis. The three-coil structure WPT system achieves CC/CV output characteristics through the topology self-switching by changing the working states of two relays. Based on the proposed CC/CV WPT system self-switching topology, an experimental platform was built, and experiments were conducted to verify the correctness of the theoretical analysis. The experimental results show that the proposed self-switching topology can achieve CC/CV switching, and the system can achieve a maximum efficiency of 89.8% at a power of 225.8 W. The proposed method can effectively enhance the transmission distance and solve the problems of overcharging or undercharging of the battery. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 9","pages":"1460-1469"},"PeriodicalIF":1.1,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Searching for Stiffness Singularity Using Directional Palpation by a Microfinger and its Scanning Condition Dependence","authors":"Yuto Hori,&nbsp;Satoshi Konishi","doi":"10.1002/tee.70029","DOIUrl":"https://doi.org/10.1002/tee.70029","url":null,"abstract":"<p>Minimally invasive treatment has recently emerged as a dominant procedure, as it reduces the patients' physical burden. However, it is still limited by the lack of tactile-sensation feedback from the invading device. We have reported a technology for conducting stiffness-singularity search in an elastic object based on palpation using a microfinger that was integrated with an artificial muscle and a tactile sensor. Here, to advance the application of the technology in medical diagnosis, we focused on tumor detection facilitated by palpation diagnosis using the microfinger. Notably, the miniaturized microfinger exhibits bending actuation, which imparts it with directivity. We have demonstrated an efficient searching method for singularities based on the directivity of the microfinger. Here, we estimated the condition dependence of the search method, as it is key to achieving the application of palpation diagnosis, and confirmed the accuracy of the proposed technology for estimating singularities. Thus, we present a highly efficient search method that offers feedback on tactile information. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 7","pages":"1128-1133"},"PeriodicalIF":1.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144256565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-Stage Long-Tailed Object Detection Based on Adaptive Class Suppression Equalized Focal Loss","authors":"Qian Yang,&nbsp;Xin Feng,&nbsp;Shuqiu Tan","doi":"10.1002/tee.70027","DOIUrl":"https://doi.org/10.1002/tee.70027","url":null,"abstract":"<p>When dealing with long-tailed data, performance is degraded due to the model's bias in classifying most of the tail categories. Although good results have been achieved for long-tailed object detection, almost all long-tailed object detectors are based on a two-stage paradigm. One-stage detectors have advantages such as fast inference speed and ease of deployment, making them more common in practical applications. However, in-depth research on one-stage long-tail object detection is still lacking. Under the one-stage object detection paradigm, the main reasons for performance degradation in long-tailed object detection models are as follows: (1) the extreme imbalance between foreground samples and background samples; (2) the long-tailed problem among foreground categories; (3) insufficient diversity of samples in the tail categories, which makes it difficult for the model to focus on the important features of the tail samples. To address these problems, this paper proposes the adaptive class suppression equalized focal loss (AEFL), which introduces adaptive class suppression weight parameters to dynamically suppress excessive negative gradients generated by a large number of negative samples during training, thereby improving tail category accuracy. Meanwhile, a channel self-attention mechanism is introduced in the C5 and C4 layers of the FPN, which contain rich semantic information, to enable the implicit clustering of objects of the same category and enhance semantic continuity. The improved CSA-FPN helps the model pay more attention to important features, and when dealing with long-tailed categories, it can better focus on the features of these categories, further enhancing the effect of AEFL. The methods in this paper are extensively tested on the LVIS-0.5 dataset and a long-tailed object detection dataset on the Kaggle platform, and the experimental results show that the proposed methods outperform most of the existing one-stage detection networks on two different long-tailed datasets. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.</p>","PeriodicalId":13435,"journal":{"name":"IEEJ Transactions on Electrical and Electronic Engineering","volume":"20 9","pages":"1424-1435"},"PeriodicalIF":1.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}