Submit to Special Issue Submit Abstract to Special Issue Review for Energies Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Related Special Issue
Published Papers

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "F6: High Voltage".

Deadline for manuscript submissions: 5 November 2026 | Viewed by 3798

Share This Special Issue

Special Issue Editors

Dr. Chuyan Zhang

E-Mail Website
Guest Editor

School of Artificial Intelligence, China University of Geosciences Beijing, Beijing 100083, China
Interests: high-voltage external insulation; AI+electrical engineering; electrical measurement and sensing; dielectrics and electrical discharges
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Xiaobo Meng

E-Mail Website
Guest Editor

School of Mechanical and Electrical Engineering, Guangzhou University, Guangzhou 510006, China
Interests: high voltage and insulation technology; electrical engineering materials; organic composite materials; surface and gas discharge
Special Issues, Collections and Topics in MDPI journals

Dr. Hao Yang

E-Mail Website
Guest Editor

School of Electronics and Information, Xi'an Polytechnic University, Xi'an 710048, China
Interests: novel technologies in high voltage engineering; state monitoring and fault diagnosis of power transmission and transformation equipment; physics of electrical discharges and plasma applications
Special Issues, Collections and Topics in MDPI journals

Dr. Zhong Wang

E-Mail Website
Guest Editor

College of Electrical Engineering, Sichuan University, Chengdu 610065, China
Interests: insulation and detection technologies for cables and bushings; silicone insulating materials
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The global energy transition and rapid renewable integration are challenging power system reliability and resilience. The failure of critical assets like dielectrics and high-voltage (HV) equipment can have catastrophic consequences. Traditional, schedule-based operation, maintenance, and inspection strategies are no longer sufficient for the complexity of modern grids. Digital transformation, leveraging big data, AI, IoT, and advanced sensing, provides a solution.

This Special Issue, “Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment,” aims to capture the state of the art and future directions in this rapidly evolving field. Our objective is to provide a comprehensive platform for researchers, engineers, and practitioners to share the innovative frameworks and technologies driving the transition from conventional OM&I to data-driven, predictive models.

We invite high-quality original research and review articles on topics including, but not limited to, the following: AI-powered diagnostics and prognostics for fault detection and life prediction; digital twins for real-time monitoring and optimization; advanced sensing and IoT for continuous multi-parameter monitoring; intelligent inspection using robotics and drones; data-driven maintenance strategies; and the cyber–physical security of these digital systems.

This Special Issue aims to foster multidisciplinary dialogue between high-voltage engineering and other fields, contributing to the innovations needed for a more reliable, efficient, and intelligent future grid. We look forward to your submissions.

Dr. Chuyan Zhang
Prof. Dr. Xiaobo Meng
Dr. Hao Yang
Dr. Zhong Wang
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

high-voltage equipment
dielectrics
artificial intelligence
predictive maintenance
digital twin
condition monitoring
multiphysics simulation
electrical sensing

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Related Special Issue

Recent Progress, Challenges and Outlooks of Insulation System in HVDC: 2nd Edition in Energies (11 articles)

Published Papers (8 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

26 pages, 2218 KB

Open AccessArticle

Method for Recognizing Partial Discharge Types in Air-Insulated Switchgear Based on CO/NO₂ Gas Component Ratio

by Ning Zhang, Yi Wang, Chunhao Lu, Zhidu Huang and Jia Zhang

Energies 2026, 19(11), 2608; https://doi.org/10.3390/en19112608 - 28 May 2026

Viewed by 79

Abstract

The safe and stable operation of air-insulated switchgear (AIS) in high-altitude and low-pressure environments is significantly affected by partial discharge (PD), which accelerates insulation aging and may threaten power system reliability. Therefore, effective online monitoring and fault diagnosis methods are of considerable engineering importance. This paper proposes a PD-type recognition method based on the concentration ratio of two characteristic decomposition gases, CO and NO₂. First, a hybrid numerical model coupling fluid dynamics and plasma chemistry was established to simulate the microscopic decomposition mechanism of air discharge. The simulation results indicate that CO and NO₂ are relatively stable and detectable among the considered air-discharge products and that their generation is promoted by increased average electron energy under low-pressure conditions. Subsequently, an experimental platform was developed to simulate three typical insulation defects, namely point discharge, air-gap discharge, and surface discharge, under different simulated altitudes. Quantitative analysis using Fourier-transform infrared spectroscopy and gas chromatography revealed clear correlations between defect type and gas concentration characteristics. Based on these results, a diagnostic criterion was established under the tested conditions: a CO/NO₂ concentration ratio less than 1 indicates the epoxy-resin-based surface discharge model, whereas a ratio greater than 1 indicates point discharge or air-gap discharge. The latter two types can be further distinguished according to the time-dependent increasing trend of the ratio for air-gap discharge. Finally, based on the observed diffusion characteristics of these gases in the laboratory switchgear model, a low-cost online detection prototype using semiconductor gas sensors was developed. Laboratory validation using three typical single-defect models showed that the proposed method achieved 100% recognition accuracy when sufficient time-series data were available. However, further field validation is required before large-scale industrial application. The proposed CO/NO₂ ratio method provides a potential low-cost auxiliary diagnostic approach for AIS insulation monitoring, particularly under high-altitude and low-pressure conditions. Full article

(This article belongs to the Special Issue Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment)

19 pages, 1816 KB

Open AccessArticle

A Data-Driven Parameter Inversion Method for Converter Valve Thyristor Levels Based on Time-Frequency-Domain Features

by Yingfeng Zhu, Donglin Xu, Ming Li, Chenhao Li, Jie Ren, Junqi Ding, Boyang Xia and Lei Pang

Energies 2026, 19(10), 2357; https://doi.org/10.3390/en19102357 - 14 May 2026

Viewed by 194

Abstract

The thyristor level is the basic unit of ultra-high-voltage and extra-high-voltage direct current (DC) converter valves, and its main-circuit parameters are important indicators for characterizing the health status of converter valves. To meet the demand for efficient detection of converter valve thyristor levels, this paper proposes a parameter inversion method for converter valve thyristor levels by combining the time-frequency-domain features of valve voltage and current, temporal characteristics of feedback signals from the thyristor-level monitoring unit, and a Grey Wolf Optimizer–Backpropagation Neural Network (GWO-BPNN). First, a six-pulse converter valve circuit simulation model is established. Based on this model, the original dataset is generated using the Latin hypercube sampling (LHS) method. Wavelet packet decomposition is then used to extract time-frequency-domain features, and dimensionality reduction is carried out by comparing the coefficient of variation and explained variance ratio so as to obtain input data suitable for neural network training. A BP neural network is then trained, and the network parameters are optimized using the Grey Wolf Optimizer to improve the accuracy and convergence speed of parameter inversion. Simulation comparison results show that the GWO-BP method is more efficient than the state equation method and is suitable for efficient inversion of damping parameters in multi-level thyristor systems. After GWO optimization, the maximum inversion errors of both parameters are reduced to below 5%. Compared with BP, GA-BP, and PSO-BP, the proposed GWO-BP model provides the best overall balance between resistance-inversion accuracy and training efficiency. By further incorporating feedback feature signals, the inversion error can be reduced to 1%. The proposed method provides a new technical route for efficient detection of thyristor converter valves and has broad application prospects. Full article

(This article belongs to the Special Issue Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment)

► Show Figures

Figure 1

22 pages, 21973 KB

Open AccessArticle

Failure Modes and Degradation Mechanisms of Thyristors Under Combined Electric and Thermal Stress

by Yingfeng Zhu, Donglin Xu, Ming Li, Chenhao Li, Fei Chen, Andong Wang, Zhiwei Cao, Wenyu Mao and Lei Pang

Energies 2026, 19(8), 1999; https://doi.org/10.3390/en19081999 - 21 Apr 2026

Viewed by 405

Abstract

The reliability of the characteristics of high-voltage (HV) thyristors is related to the operational safety of the entire HVDC project. In order to investigate the degradation mode of thyristors in HVDC projects more realistically, aging experiments were conducted on HV thyristors under the combined action of sinusoidal half-wave voltage and current in a simulated operating environment. Experimental results show that the on-state voltage, reverse recovery characteristics, and reverse leakage current of thyristors have all degraded to varying degrees during the aging process. The main failure mode of thyristors can be summarized as the failure of the reverse blocking characteristic. Microstructural characterization of failed HV thyristors is conducted to explain the degradation mechanisms, including device surface morphology and elemental composition analysis. Observations have shown that the failed thyristor silicon wafer has been burned and hollowed out, accompanied by copper impurities, and significant thermal breakdown has occurred at the edge of the anode surface of the chip. Defects in chip structure and the invasion of impurities can lead to a decrease in the minority carrier lifetime of materials, which is an important factor in the characteristics of semiconductor devices. On this basis, further simulation research is carried out to conclude that the shortening of the minority carrier lifetime of the thyristor will distort the carrier space distribution, resulting in the rise in the on-state voltage. Meanwhile, the carrier transport capability decreases, leading to a decrease in the reverse recovery speed. The energy released during the rapid generation and recombination of carriers is one of the main reasons for the failure of blocking characteristics. This work provides comprehensive insights into the failure modes and mechanisms of HV thyristors. Full article

(This article belongs to the Special Issue Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment)

► Show Figures

Figure 1

25 pages, 10113 KB

Open AccessArticle

Improved YOLO11 with Mamba-2 (SSD) and Triplet Attention for High-Voltage Bushing Fault Detection from Infrared Images

by Zili Wang, Chuyan Zhang, Mingguang Diao, Yi Xiao and Huifang Liu

Energies 2026, 19(8), 1923; https://doi.org/10.3390/en19081923 - 15 Apr 2026

Viewed by 395

Abstract

High-voltage bushings, the fault-prone key electrical components of transformers, are critical for real-time and high-accuracy fault monitoring and management. Intelligent fault detection via infrared images is plagued by low classification accuracy due to massive interference from similar tubular objects and small target characteristics. This study proposes a lightweight deep learning model, MTrip–YOLO, an improved YOLO11n integrated with Mamba-2 (Structured State Space Duality, SSD) and Triplet Attention, to achieve efficient fault monitoring in complex backgrounds. The training and validation dataset comprises open-source images, on-site data from a substation, and field-collected infrared images, categorized into four types: normal bushings, poor contact, oil shortage, and high dielectric loss faults. Mamba-2 captures the long-range global context of infrared features with its linear-complexity long-range modeling capability to enhance feature extraction, while Triplet Attention suppresses complex background radiation noise through cross-dimensional interaction without dimensionality reduction, enabling the model to focus on small targets and accurately classify bushings from morphologically similar strip-shaped objects. Experimental results show that MTrip–YOLO achieves a top mAP50 of 91.6% and a minimal parameter count of 1.9 M, outperforming Faster R-CNN, RT-DETR, and YOLO26n across all evaluated metrics and being potentially suitable for edge deployment on UAV-mounted or handheld infrared platforms, pending hardware validation on embedded computing devices. Ablation experiments verify the independent contributions of Mamba-2 (0.8027% mAP50 improvement) and Triplet Attention (0.89327% mAP50 improvement), with a synergistic effect from their combination. MTrip–YOLO provides a potential edge-deployable solution for high-voltage bushing fault monitoring, offering important application value for the intelligent operation and maintenance of substations. Full article

(This article belongs to the Special Issue Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment)

► Show Figures

Figure 1

17 pages, 4638 KB

Open AccessArticle

Simulation Analysis of the Effects of Barrier Defects on the Electro–Thermal Fields of the XLPE Cable Buffer Layer

by Shili Liu and Zhenhao Wei

Energies 2026, 19(6), 1433; https://doi.org/10.3390/en19061433 - 12 Mar 2026

Viewed by 532

Abstract

With the increasing number of failures in high-voltage cross-linked polyethylene cables caused by buffer layer ablation, it is of great significance to investigate the electro–thermal coupling characteristics and ablation driving mechanisms under different defect conditions. Based on a multiphysics coupling model, an electro–thermal coupled simulation of the cable buffer layer and corrugated aluminum sheath was carried out, considering three typical defect types: air-gap barrier, moisture ingress, and white-powder barrier. The distributions of air-gap electric field, interfacial current density, temperature, and heat source were systematically analyzed. From the perspective of ablation mechanisms, the maximum air-gap electric field and its spatial location, as well as the maximum temperature of the buffer layer and its corresponding region, were investigated under different defect conditions. Meanwhile, the probabilities of electrical ablation and thermal ablation, together with their corresponding threshold parameters, were quantitatively evaluated. The results show that when an air-gap barrier exists between the buffer layer and the aluminum sheath, air breakdown may occur when the air-gap thickness is approximately 0.01–0.05 mm. When the buffer layer is moisture-contaminated and the defect length exceeds approximately 2 m, the buffer layer temperature may exceed 165 °C. When white-powder precipitates in the buffer layer, partial discharge may be initiated at the early stage. With the increase in powder barrier proportion, the buffer layer temperature may exceed approximately 220 °C. It should be noted that these critical characteristics are obtained under the simulation conditions of this study. The specific values depend on material parameters and operating conditions and can provide theoretical support for cable operation condition assessment. Full article

(This article belongs to the Special Issue Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment)

► Show Figures

Figure 1

24 pages, 3898 KB

Open AccessArticle

Structural Design and Electromechanical Performance Verification of High-Voltage Optical Fiber Composite Insulators Based on Finite Element Simulation

by Jianbing Fu, Yanfeng Gao, Liming Wang, Yi Lu, Fanghui Yin, Xiaolong Huang, Dexuan Cai, Dongsheng He and Kang Wang

Energies 2026, 19(5), 1202; https://doi.org/10.3390/en19051202 - 27 Feb 2026

Viewed by 460

Abstract

Silicone rubber optical fiber composite insulators introduce interface defects due to embedded optical fibers, and their structural design remains immature, resulting in inadequate interface sealing performance. In actual operation, the combined effects of high electric fields, high humidity and heat, and mechanical loads lead to frequent failures. This study proposes replacing conventional silicone rubber with cycloaliphatic epoxy resin (CEP), which exhibits superior aging resistance, to enhance long-term operational reliability. However, the correlation mechanism between the structural parameters of CEP optical fiber insulators and their electromechanical properties remains unclear, lacking corresponding design basis. Therefore, based on finite element simulation technology, this study systematically analyzed the influence patterns of core rod diameter, fiber implantation method, spiral groove angle, fiber implantation quantity, and voltage equalization ring structural parameters (outer diameter, circular tube radius, shielding depth) on their mechanical and electrical properties. Research findings indicate that in terms of mechanical properties, the helical groove structure with a 40 mm core rod diameter, a groove angle of 135°, and six embedded optical fibers exhibits the lowest optical fiber strain. In terms of electrical performance, the minimum peak electric field strength at the end of the insulator occurs when the equalizing ring has an outer diameter of 370 mm, the circular tube radius is 25 mm, and the shielding depth is 50 mm, reaching only 4.6 kV/cm, which meets the requirements of DL/T 1000.3-2015. This study establishes optimization principles for key structural parameters of CEP optical fiber composite insulators, offering significant engineering value for enhancing the overall performance of optical fiber composite insulators and improving the operational safety of power systems. Full article

(This article belongs to the Special Issue Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment)

► Show Figures

Figure 1

15 pages, 2809 KB

Open AccessArticle

Research on an Intelligent Sealed Neutral Point Protection Device for High-Altitude Transformers

by Wen Yan, Xiaohui Li, Fujie Wang, Huifang Dong, Zhongqi Zhao, Jinpeng Gao and Xutao Han

Energies 2026, 19(4), 906; https://doi.org/10.3390/en19040906 - 9 Feb 2026

Viewed by 382

Abstract

To address the malfunction and unreliable operation of traditional open discharge gaps in high-altitude environments (with sandstorms and low pressure), which are prone to interference from factors like electrode corrosion and contamination, this study proposes an intelligent sealed neutral point protection device for transformers. Its core is a sealed discharge gap filled with nitrogen gas, effectively isolating it from external conditions and significantly stabilizing the power frequency discharge voltage. Innovatively, an active breakdown technology is introduced. Overvoltage signals at the transformer neutral point are acquired in real time via a capacitive voltage divider. After processing by a microcontroller unit (MCU), if both the amplitude and duration meet the preset thresholds, the MCU triggers a pulse to actively induce a discharge at the gap’s low-voltage end, enabling controlled breakdown. This allows the transient discharge voltage to be raised to 3–4 times the steady-state value, avoiding overlap with the surge arrester’s residual voltage. Tests confirm that the gap breaks down stably only when both amplitude and duration conditions are met, remaining reliable otherwise. This design successfully resolves the critical issues of failure and maloperation under both steady-state and transient overvoltages in high-altitude settings, significantly improving protection selectivity and reliability, and offering a novel solution for transformer safety in such regions. Full article

(This article belongs to the Special Issue Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment)

► Show Figures

Figure 1

13 pages, 2264 KB

Open AccessArticle

Ampacity Calculation Method for Overhead Conductors in High-Altitude Areas Based on Numerical Simulation

by Jia Li, Wei Liu, Hanyue Zhang and Xuandong Liu

Energies 2026, 19(2), 392; https://doi.org/10.3390/en19020392 - 13 Jan 2026

Viewed by 688

Abstract

Overhead transmission lines are critical carriers for power delivery, directly influencing the security of the power system. In high-altitude areas, special environmental conditions such as low air pressure and intense solar radiation significantly change the heat absorption and dissipation characteristics of conductors. Therefore, it is necessary to correct the overhead conductors’ ampacity in such areas to ensure safe operation. However, the ampacity calculation method and high-altitude ampacity correction coefficients proposed in existing standards have significant limitations, and there are also large errors in the calculation results. Therefore, based on the system of partial differential equations proposed in the “Guidelines for Calculating the Current-Carrying Capacity of Transmission Conductors at High Altitudes” and the suggestions for high-altitude meteorological parameter modifications from existing standards, this paper establishes a three-dimensional finite element model to study the ampacity calculation method for overhead conductors in high-altitude areas. The results show that a significant thermal shielding effect exists among bundled conductors, and meteorological condition variations significantly influence the temperature distribution of the conductors and their surrounding space. At altitudes of 4000~5000 m, the altitude correction coefficient for both twin-bundle and quad-bundle conductors is −0.06 A∙m⁻¹ under specific conservative conditions. Full article

(This article belongs to the Special Issue Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment)

► Show Figures

Journal Menu

Journal Browser

Digital and Intelligent Operations, Maintenance, and Inspection of Dielectrics and High-Voltage Equipment

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (8 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI