This study explores the breakdown characteristics and discharge modes in a parallel plate air dielectric barrier discharge system using repetitive nanosecond pulses, with pulse repetition frequencies (PRFs) from 0.1 to 100 kHz. It examines how pulse parameters—PRF, pulse number and gas pressure—affect the memory effect, leveraging current and voltage measurements, fast imaging and optical emission spectroscopy. The findings show that higher PRFs lead to a reduction in breakdown voltage well below the streamer breakdown threshold. We argue that this effect may be attributed to the cumulative buildup of metastable species and negative ions in the discharge gap which could sustain free electrons in-between the voltage pulses. Despite observing increased energy deposition with higher PRFs, the impact on filament formation was minimal, highlighting a strong dependence of discharge morphology on the accumulation of plasma-produced species. This research studies provides valuable insights for controlling discharge regimes in applications such as plasma-assisted combustion, surface treatment and air treatment by clarifying the interactions between discharge mechanisms at different PRFs and pressures.
{"title":"Breakdown and Discharge Characteristics of High Repetition Frequency Nanosecond Pulsed Air Dielectric Barrier Discharge","authors":"Mahreen, Dongxuan Xu, Denis Shaw, Peter Bruggeman","doi":"10.1049/hve2.70140","DOIUrl":"https://doi.org/10.1049/hve2.70140","url":null,"abstract":"This study explores the breakdown characteristics and discharge modes in a parallel plate air dielectric barrier discharge system using repetitive nanosecond pulses, with pulse repetition frequencies (PRFs) from 0.1 to 100 kHz. It examines how pulse parameters—PRF, pulse number and gas pressure—affect the memory effect, leveraging current and voltage measurements, fast imaging and optical emission spectroscopy. The findings show that higher PRFs lead to a reduction in breakdown voltage well below the streamer breakdown threshold. We argue that this effect may be attributed to the cumulative buildup of metastable species and negative ions in the discharge gap which could sustain free electrons in-between the voltage pulses. Despite observing increased energy deposition with higher PRFs, the impact on filament formation was minimal, highlighting a strong dependence of discharge morphology on the accumulation of plasma-produced species. This research studies provides valuable insights for controlling discharge regimes in applications such as plasma-assisted combustion, surface treatment and air treatment by clarifying the interactions between discharge mechanisms at different PRFs and pressures.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"29 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shixun Hu, Cheng Tong, Xiyu Zhang, Changhong Li, Wangjie Zeng, Shangshi Huang, Chi Yao, Xiongjie Yang, Si Qin, Yiyi Zhang, Yuntian Ge, Qi Li, Jinliang He
Maleic anhydride (MAH) grafting modification is an effective approach to enhance the insulating performance of polyethylene (PE) cable insulations. However, the high polarity of MAH often causes considerable dielectric loss, making it unsuitable for AC systems. This study proposes a strategy to address this issue by adopting an ultralow-content MAH grafting to limit polarity introduction while maintaining enhanced electrical performance and by utilising the short-branch structural differences between linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE) to regulate MAH relaxation and dielectric loss. Experimental results verified the feasibility of this approach: Thermal and mechanical properties were only slightly affected, whereas resistivity increased significantly. The low-frequency (less than 100 Hz) dielectric loss at 90°C, particularly in short-branched LLDPE, was effectively suppressed. Molecular dynamics simulations further revealed that the abundant short branches in LLDPE can restrict the motion of MAH groups, thereby reducing the intermolecular friction. Combined with the charge trapping effect of MAH, this yields a substantial suppression of high-temperature dielectric loss. The results suggest that ultralow-content MAH-grafted LLDPE is a promising recyclable cable insulating material for high-capacity power distribution systems.
{"title":"Dielectric Loss Suppression of Polyethylene Cable Insulation by Motion Restriction of Ultralow-Content Grafted Maleic Anhydride","authors":"Shixun Hu, Cheng Tong, Xiyu Zhang, Changhong Li, Wangjie Zeng, Shangshi Huang, Chi Yao, Xiongjie Yang, Si Qin, Yiyi Zhang, Yuntian Ge, Qi Li, Jinliang He","doi":"10.1049/hve2.70137","DOIUrl":"https://doi.org/10.1049/hve2.70137","url":null,"abstract":"Maleic anhydride (MAH) grafting modification is an effective approach to enhance the insulating performance of polyethylene (PE) cable insulations. However, the high polarity of MAH often causes considerable dielectric loss, making it unsuitable for AC systems. This study proposes a strategy to address this issue by adopting an ultralow-content MAH grafting to limit polarity introduction while maintaining enhanced electrical performance and by utilising the short-branch structural differences between linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE) to regulate MAH relaxation and dielectric loss. Experimental results verified the feasibility of this approach: Thermal and mechanical properties were only slightly affected, whereas resistivity increased significantly. The low-frequency (less than 100 Hz) dielectric loss at 90°C, particularly in short-branched LLDPE, was effectively suppressed. Molecular dynamics simulations further revealed that the abundant short branches in LLDPE can restrict the motion of MAH groups, thereby reducing the intermolecular friction. Combined with the charge trapping effect of MAH, this yields a substantial suppression of high-temperature dielectric loss. The results suggest that ultralow-content MAH-grafted LLDPE is a promising recyclable cable insulating material for high-capacity power distribution systems.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"30 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. S. Mikhailov, I. L. Muzyukin, I. V. Uimanov, D. L. Shmelev, S. A. Barengolts
This paper presents the results of an experimental study aimed at determining the threshold current for triggering a vacuum arc discharge, the probability of arc ignition and the average arc operation time depending on the current for tungsten and copper electrodes. It has been shown that the cutoff current of a vacuum arc varies widely under constant experimental conditions. The threshold current for tungsten cathodes is higher than for copper ones. For both materials, there is a nonzero probability of arc ignition at currents significantly lower than the average threshold. At the same time, the exponential dependence of the average arc operation time on the current is preserved.
{"title":"Threshold Currents of Vacuum Arcs With Tungsten and Copper Cathodes","authors":"P. S. Mikhailov, I. L. Muzyukin, I. V. Uimanov, D. L. Shmelev, S. A. Barengolts","doi":"10.1049/hve2.70151","DOIUrl":"https://doi.org/10.1049/hve2.70151","url":null,"abstract":"This paper presents the results of an experimental study aimed at determining the threshold current for triggering a vacuum arc discharge, the probability of arc ignition and the average arc operation time depending on the current for tungsten and copper electrodes. It has been shown that the cutoff current of a vacuum arc varies widely under constant experimental conditions. The threshold current for tungsten cathodes is higher than for copper ones. For both materials, there is a nonzero probability of arc ignition at currents significantly lower than the average threshold. At the same time, the exponential dependence of the average arc operation time on the current is preserved.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"47 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zihang Xu, Zepeng Lv, Chen Zhang, Kai Wu, Peter Morshuis, Aurore Claverie
For dielectric elastomer generators (DEG), electrical breakdown is the main failure mode during their working cycle. The application of self-clearing electrodes is of great significance to avoid a single breakdown leading to the failure of the entire generator. Electrodes based on single-walled carbon nanotubes (SWCNT) have proven to have excellent self-clearing performance and thus are suitable for elastomers. Similar to metal electrodes, Joule heating generated during the breakdown process is used to self-combust, forming nonconductive regions at the defect location. Because breakdown is a prerequisite for self-clearing, it is necessary to understand how the dielectric strength of the DEG changes during a working cycle. Therefore, this article investigates the changes in breakdown characteristics and self-clearing during the dynamic process of the DEG working cycle. The breakdown field strength of the DEG was tested, and it was found that the prominent cause of failure after introducing SWCNT electrodes was buckling instability and uneven deformation due to electrode nonuniformity. A detailed study of the self-clearing process was conducted. A good self-clearing performance of SWCNT electrodes during the DEG power generation cycle is related to the energy supplied by the parallel capacitance in the system. To investigate the influence of the parallel capacitance on self-clearing and to better design the total capacitance in the real DEG device, the energy required for self-clearing was analysed and clarified. This study provides an experimental basis for the development of reliable DEG devices.
{"title":"The Breakdown and Self-Clearing Performance During the Energy Harvesting Process of Dielectric Elastomer Generators Using Single-Walled Carbon Nanotubes Electrodes","authors":"Zihang Xu, Zepeng Lv, Chen Zhang, Kai Wu, Peter Morshuis, Aurore Claverie","doi":"10.1049/hve2.70117","DOIUrl":"https://doi.org/10.1049/hve2.70117","url":null,"abstract":"For dielectric elastomer generators (DEG), electrical breakdown is the main failure mode during their working cycle. The application of self-clearing electrodes is of great significance to avoid a single breakdown leading to the failure of the entire generator. Electrodes based on single-walled carbon nanotubes (SWCNT) have proven to have excellent self-clearing performance and thus are suitable for elastomers. Similar to metal electrodes, Joule heating generated during the breakdown process is used to self-combust, forming nonconductive regions at the defect location. Because breakdown is a prerequisite for self-clearing, it is necessary to understand how the dielectric strength of the DEG changes during a working cycle. Therefore, this article investigates the changes in breakdown characteristics and self-clearing during the dynamic process of the DEG working cycle. The breakdown field strength of the DEG was tested, and it was found that the prominent cause of failure after introducing SWCNT electrodes was buckling instability and uneven deformation due to electrode nonuniformity. A detailed study of the self-clearing process was conducted. A good self-clearing performance of SWCNT electrodes during the DEG power generation cycle is related to the energy supplied by the parallel capacitance in the system. To investigate the influence of the parallel capacitance on self-clearing and to better design the total capacitance in the real DEG device, the energy required for self-clearing was analysed and clarified. This study provides an experimental basis for the development of reliable DEG devices.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"21 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shengtao Li, Lisheng Zhong, Davide Fabiani, Chong Zhang, Shihang Wang, Jinghui Gao, Roland D. Zhang
<div>High-voltage direct current (HVDC) cables are growing rapidly all over the world due to the development of offshore wind power interconnections, cross-island power interconnections, etc. Extensive research has been conducted and many achievements have been made in the study of theoretical issues of HVDC insulation, structural design and manufacture of HVDC cables with the corresponding accessories, as well as in condition monitoring technology. However, as the voltage level of the cable is raised, the transmission capacity is increased and the transmission distance is extended, there are still many challenging problems to be solved, ranging from the material optimisation and design updates to technological breakthroughs. Therefore, it is necessary to conduct more extensive study and discussion on the research progress and technological development of HVDC cables. This special issue highlights cutting-edge research focused on advanced testing methods of HVDC cable and improved insulating materials for HVDC cable. We are pleased to introduce ten high-quality articles selected for this issue: <ul> <li> <p>Giovanni Mazzanti reviews the existing testing techniques for HVDC cable systems, considers development tests, pre-qualification tests, extension of qualification test, type tests, routine tests, sample tests and after installation tests. An example of an innovative sea trial testing procedure is shown, which is the outcome of a fruitful partnership between a cable manufacturer and the national transmission system operator in Italy.</p> </li> <li> <p>Gian Carlo Montanari et al. present a theory-driven and measurement-based procedure, having the purpose to minimise partial discharge (PD) inception risk. This procedure is based on stepwise voltage application during cable energisation. The fundamental idea behind the proposed approach stems from considering that the jump voltage is the trigger of PD occurrence. It is shown that compared with the conventional energisation consisting of rapidly increasing voltage, the stepwise approach can reduce the risk of PD inception and related extrinsic ageing, even for the steady state voltages larger than PDIV<sub>DC</sub>.</p> </li> <li> <p>Cheng Zhang et al. propose a PD vibration diagnosis methodology using the embedded fibre based on the heterodyne interferometric phase-sensitive optical time domain reflectometry (<i>φ</i>-OTDR) and Hilbert demodulation, to detect the PD of HVDC submarine cable. The proposed method is verified by PD experiment with pre-set defects in 220 kV submarine cables under DC voltage.</p> </li> <li> <p>Shengtao Li and Shihang Wang et al. propose and substantiate the concept of regulating the high-temperature stabilities of crosslinked polyethylene (XLPE) insulation by the synergistic effects of antioxidants and crosslinking agents. This study illustrates the positive effect of antioxidants on the antiscorching characteristic, thermal elongation and oxidation induction time of XL
随着海上风电互联、跨岛电力互联等的发展，高压直流电缆在世界范围内迅速发展。在高压直流绝缘理论问题、高压直流电缆及其附件的结构设计与制造、状态监测技术等方面进行了广泛的研究，取得了许多成果。然而，随着电缆电压等级的提高、传输容量的增加和传输距离的延长，从材料的优化、设计的更新到技术的突破，仍有许多具有挑战性的问题需要解决。因此，有必要对高压直流电缆的研究进展和技术发展进行更广泛的研究和探讨。本期特刊重点介绍了高压直流电缆的先进测试方法和改进的高压直流电缆绝缘材料的前沿研究。我们很高兴为您介绍本期精选的十篇高质量文章：Giovanni Mazzanti回顾了高压直流电缆系统的现有测试技术，考虑了开发测试、资格预审测试、资格延期测试、型式测试、常规测试、样品测试和安装后测试。展示了一个创新的海上试验程序的例子，这是电缆制造商与意大利国家传输系统运营商之间富有成效的伙伴关系的结果。Gian Carlo Montanari等人提出了一个理论驱动和基于测量的程序，目的是尽量减少局部放电（PD）的开始风险。这个程序是基于电缆通电过程中逐步施加的电压。提出的方法背后的基本思想源于考虑跳跃电压是PD发生的触发因素。结果表明，即使稳态电压大于PDIVDC，与传统的快速增加电压的激励方法相比，逐步激励方法也可以降低PD发生的风险和相关的外在老化。Cheng Zhang等人提出了一种基于外差干涉相敏光学时域反射（φ-OTDR）和Hilbert解调的嵌入式光纤PD振动诊断方法，用于检测HVDC海底电缆的PD。通过直流电压下220kv海底电缆预置缺陷的局部放电实验验证了该方法的有效性。李盛涛、王世航等人提出并证实了通过抗氧化剂和交联剂的协同作用调节交联聚乙烯（XLPE）绝缘高温稳定性的概念。研究表明，抗氧剂对交联聚乙烯保温材料的抗焦性能、热伸长率和氧化诱导时间的影响与过氧化二氨基含量有关。高景辉、钟立生等研究了双层XLPE （H-XLPE）中电荷积累的基本机制和相关的同质结效应。研究结果为阐明界面面积对影响海底电缆系统可靠性和稳定性的电荷积累的作用提供了实验依据和理论线索。张冲和钟立生等人开发了一种基于时变极化电流的特低频（ELF）介电分析方法，用于XLPE副产物的无损检测。提出的极低频介电分析方法实现了电缆副产物的无损检测，为电缆脱气效果评价开辟了新的途径。周元祥等人将稳压剂蒽酮加入到XLPE中，实现了场驱动的自适应迁移和电荷捕获，从而动态调节局部电场。该方法抑制了电荷注入和输运，显著降低了内部电场畸变，产生了负电场系数效应。Isabella Nett和Willem Leterme研究了润滑剂对高压直流电缆接头宏观界面电荷动力学的影响。研究结果表明，润滑剂的扩散影响了界面的体积性质和电荷积聚，并强调了润滑剂类型的巨大影响。这些结果对于了解高压直流电缆系统中电缆接头和绝缘材料的长期性能至关重要。李中磊等人提出了一种基于无损光学成像的三维（3D）重建方法来分析机械弯曲下聚丙烯（PP）电缆绝缘中的电树传播。该技术将聚焦叠加光学成像与特征融合算法相结合，跨深度层分割聚焦区域，实现了PP均聚物（PPH）、嵌段共聚物（PPB）和弹性体混合（PP/TPE）样品的电树三维重建。 Man Xu等研究了弹性体增韧PP绝缘，以满足绿色非交联PP电缆在高压直流输电中的应用要求。研究了在等规聚丙烯（iPP）中加入β-成核剂形成β-晶体，并改善了其高温直流特性。总之，本期特刊介绍了高压直流电缆先进测试方法和改进绝缘材料的最新进展。我们希望读者能发现这本合集有见地、有教育意义和鼓舞人心。
{"title":"Guest Editorial: Research Progress and Technology Development of HVDC Cable: Part I","authors":"Shengtao Li, Lisheng Zhong, Davide Fabiani, Chong Zhang, Shihang Wang, Jinghui Gao, Roland D. Zhang","doi":"10.1049/hve2.70148","DOIUrl":"https://doi.org/10.1049/hve2.70148","url":null,"abstract":"<div>High-voltage direct current (HVDC) cables are growing rapidly all over the world due to the development of offshore wind power interconnections, cross-island power interconnections, etc. Extensive research has been conducted and many achievements have been made in the study of theoretical issues of HVDC insulation, structural design and manufacture of HVDC cables with the corresponding accessories, as well as in condition monitoring technology. However, as the voltage level of the cable is raised, the transmission capacity is increased and the transmission distance is extended, there are still many challenging problems to be solved, ranging from the material optimisation and design updates to technological breakthroughs. Therefore, it is necessary to conduct more extensive study and discussion on the research progress and technological development of HVDC cables. This special issue highlights cutting-edge research focused on advanced testing methods of HVDC cable and improved insulating materials for HVDC cable. We are pleased to introduce ten high-quality articles selected for this issue: <ul>\u0000<li>\u0000<p>Giovanni Mazzanti reviews the existing testing techniques for HVDC cable systems, considers development tests, pre-qualification tests, extension of qualification test, type tests, routine tests, sample tests and after installation tests. An example of an innovative sea trial testing procedure is shown, which is the outcome of a fruitful partnership between a cable manufacturer and the national transmission system operator in Italy.</p>\u0000</li>\u0000<li>\u0000<p>Gian Carlo Montanari et al. present a theory-driven and measurement-based procedure, having the purpose to minimise partial discharge (PD) inception risk. This procedure is based on stepwise voltage application during cable energisation. The fundamental idea behind the proposed approach stems from considering that the jump voltage is the trigger of PD occurrence. It is shown that compared with the conventional energisation consisting of rapidly increasing voltage, the stepwise approach can reduce the risk of PD inception and related extrinsic ageing, even for the steady state voltages larger than PDIV<sub>DC</sub>.</p>\u0000</li>\u0000<li>\u0000<p>Cheng Zhang et al. propose a PD vibration diagnosis methodology using the embedded fibre based on the heterodyne interferometric phase-sensitive optical time domain reflectometry (<i>φ</i>-OTDR) and Hilbert demodulation, to detect the PD of HVDC submarine cable. The proposed method is verified by PD experiment with pre-set defects in 220 kV submarine cables under DC voltage.</p>\u0000</li>\u0000<li>\u0000<p>Shengtao Li and Shihang Wang et al. propose and substantiate the concept of regulating the high-temperature stabilities of crosslinked polyethylene (XLPE) insulation by the synergistic effects of antioxidants and crosslinking agents. This study illustrates the positive effect of antioxidants on the antiscorching characteristic, thermal elongation and oxidation induction time of XL","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"20 1","pages":"1347-1348"},"PeriodicalIF":4.4,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145893850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reviews the existing testing techniques for high voltage direct current (HVDC) cable systems, following as a backbone the structure of CIGRE Technical Brochure (TB) 852:2021 ‘Recommendations for testing DC extruded cable systems for power transmission at a rated voltage up to 800 kV’ because it has a fairly similar structure to CIGRE TB 853:2021 for lapped DC cables, and especially because of the impressive spread of HVDC extruded cables experienced worldwide in the last 25 years. The review considers development tests, pre-qualification tests, extension of qualification test, type tests (with hints at IEEE 1732-2017 for space charge measurements in the qualification of HVDC extruded cables), routine tests (with hints at IEEE 2862-2020 for routine tests of HVDC extruded cable system joints), sample tests and after installation tests. The review also analyses CIGRE TB 853 for lapped HVDC cable systems, as these cables remain unbeaten for submarine applications at the highest sea depths. The main novelties of CIGRE TB 852 and 853 with respect to previous standards for HVDC cable systems (mainly CIGRE TB 496 and IEC 62895 for extruded cables and CIGRE Electra 189:2000 for lapped cables) are put under the spotlight—with focus on the so-called temporary over-voltage tests—together with the limits and gaps of CIGRE TB 852. The main HVDC cable system testing equipment that is usually employed for electro-thermal tests is also treated. Emphasis is given to CIGRE TB 490 to treat the peculiarities of submarine cable systems, as well as to mechanical tests, having CIGRE TB 623 as a reference, with particular focus on the special sea trial tests. An example of an innovative sea trial testing procedure is shown, which is the outcome of a fruitful partnership between a cable manufacturer and the national Transmission System Operator in Italy.
{"title":"HVDC Cable System Testing","authors":"Giovanni Mazzanti","doi":"10.1049/hve2.70121","DOIUrl":"https://doi.org/10.1049/hve2.70121","url":null,"abstract":"This paper reviews the existing testing techniques for high voltage direct current (HVDC) cable systems, following as a backbone the structure of CIGRE Technical Brochure (TB) 852:2021 ‘Recommendations for testing DC extruded cable systems for power transmission at a rated voltage up to 800 kV’ because it has a fairly similar structure to CIGRE TB 853:2021 for lapped DC cables, and especially because of the impressive spread of HVDC extruded cables experienced worldwide in the last 25 years. The review considers development tests, pre-qualification tests, extension of qualification test, type tests (with hints at IEEE 1732-2017 for space charge measurements in the qualification of HVDC extruded cables), routine tests (with hints at IEEE 2862-2020 for routine tests of HVDC extruded cable system joints), sample tests and after installation tests. The review also analyses CIGRE TB 853 for lapped HVDC cable systems, as these cables remain unbeaten for submarine applications at the highest sea depths. The main novelties of CIGRE TB 852 and 853 with respect to previous standards for HVDC cable systems (mainly CIGRE TB 496 and IEC 62895 for extruded cables and CIGRE Electra 189:2000 for lapped cables) are put under the spotlight—with focus on the so-called temporary over-voltage tests—together with the limits and gaps of CIGRE TB 852. The main HVDC cable system testing equipment that is usually employed for electro-thermal tests is also treated. Emphasis is given to CIGRE TB 490 to treat the peculiarities of submarine cable systems, as well as to mechanical tests, having CIGRE TB 623 as a reference, with particular focus on the special sea trial tests. An example of an innovative sea trial testing procedure is shown, which is the outcome of a fruitful partnership between a cable manufacturer and the national Transmission System Operator in Italy.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"56 1","pages":"1349-1370"},"PeriodicalIF":4.4,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145893859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chuansheng Zhang, Chengyan Ren, Yu Feng, Yi Luo, Cheng Zhang, Tao Shao
Film capacitors, essential for energy storage in power systems, benefit from reduced film thickness to increase capacitance and lower costs. While the inverse power law traditionally links higher electric strength with thinner films, its validity diminishes below a critical thickness. This study investigates the thickness-dependent dielectric breakdown characteristics (3.4–15 μm) of biaxially oriented polypropylene (BOPP) films under varying electrical polarities, focusing on surface structures, surface charge dynamics and trap mechanisms. Experimental results identify a transition thickness of 9 μm, beyond which the inverse power law holds. Below this threshold, breakdown field strength declines with thinning, correlating with reduced surface charge dissipation ratios and slower decay rates. Enhanced breakdown strength is observed when surface charge retention is higher. Additionally, thinner films exhibit proportional increases in shallow trap density, weakening dielectric performance. Excessive deep trap density further reduces breakdown strength. These findings highlight the critical role of surface effects and trap density in governing the dielectric stability of ultrathin BOPP films, providing insights for optimising capacitor film design.
{"title":"Dielectric Breakdown Characteristics of Biaxially Oriented Polypropylene Films: Surface Structures on Thickness Dependence","authors":"Chuansheng Zhang, Chengyan Ren, Yu Feng, Yi Luo, Cheng Zhang, Tao Shao","doi":"10.1049/hve2.70139","DOIUrl":"https://doi.org/10.1049/hve2.70139","url":null,"abstract":"Film capacitors, essential for energy storage in power systems, benefit from reduced film thickness to increase capacitance and lower costs. While the inverse power law traditionally links higher electric strength with thinner films, its validity diminishes below a critical thickness. This study investigates the thickness-dependent dielectric breakdown characteristics (3.4–15 μm) of biaxially oriented polypropylene (BOPP) films under varying electrical polarities, focusing on surface structures, surface charge dynamics and trap mechanisms. Experimental results identify a transition thickness of 9 μm, beyond which the inverse power law holds. Below this threshold, breakdown field strength declines with thinning, correlating with reduced surface charge dissipation ratios and slower decay rates. Enhanced breakdown strength is observed when surface charge retention is higher. Additionally, thinner films exhibit proportional increases in shallow trap density, weakening dielectric performance. Excessive deep trap density further reduces breakdown strength. These findings highlight the critical role of surface effects and trap density in governing the dielectric stability of ultrathin BOPP films, providing insights for optimising capacitor film design.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"8 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jilai Xu, Baoquan Wan, Jun Zhao, Jiangong Zhang, Min Dai
In the de-icing process of double-circuit direct current (DC) transmission lines on the same tower, an operational condition exists in which one circuit is de-energised and utilised as part of the de-icing current path, specifically designed for grounding line de-icing purposes. Accurate calculation of the floating potential of the out-of-service line is crucial for the design of de-icing devices. This study employs the upstream finite element method combined with a potential prediction correction approach to determine the floating potential of de-energised conductors. A field-circuit model is proposed for calculating conductor floating potentials under single-circuit outage conditions in double-circuit DC transmission lines. The charge dissipation process through grounding resistors with varying values is also analysed. In a ± 500 kV case study, the relative errors between the circuit model and electric field model calculations for the positive and negative conductor floating potentials are merely 3.66% and 0.89%, respectively, verifying the validity of the circuit model. The equivalent resistance of ion flow fields reaches magnitudes of 106 Ω, significantly exceeding the intrinsic resistance of the conductors. When using voltage-limiting resistors, conductor voltages decrease significantly with a 0.5-MΩ resistor, and the calculated floating potentials become 8.702 kV and −5.849 kV, reflecting reductions of 84.8% and 88.4%, respectively. This research demonstrates that the proposed method provides an effective solution for floating potential calculation during single-circuit outages in double-circuit DC lines. The analysis of charge dissipation through voltage-limiting resistors offers technical support for designing DC de-icing devices.
{"title":"Analysis of the Field Circuit Model for the Suspension Potential of Conductors in Single-Circuit Outage of Double-Circuit DC Transmission Lines on the Same Tower","authors":"Jilai Xu, Baoquan Wan, Jun Zhao, Jiangong Zhang, Min Dai","doi":"10.1049/hve2.70128","DOIUrl":"https://doi.org/10.1049/hve2.70128","url":null,"abstract":"In the de-icing process of double-circuit direct current (DC) transmission lines on the same tower, an operational condition exists in which one circuit is de-energised and utilised as part of the de-icing current path, specifically designed for grounding line de-icing purposes. Accurate calculation of the floating potential of the out-of-service line is crucial for the design of de-icing devices. This study employs the upstream finite element method combined with a potential prediction correction approach to determine the floating potential of de-energised conductors. A field-circuit model is proposed for calculating conductor floating potentials under single-circuit outage conditions in double-circuit DC transmission lines. The charge dissipation process through grounding resistors with varying values is also analysed. In a ± 500 kV case study, the relative errors between the circuit model and electric field model calculations for the positive and negative conductor floating potentials are merely 3.66% and 0.89%, respectively, verifying the validity of the circuit model. The equivalent resistance of ion flow fields reaches magnitudes of 10<sup>6</sup> Ω, significantly exceeding the intrinsic resistance of the conductors. When using voltage-limiting resistors, conductor voltages decrease significantly with a 0.5-MΩ resistor, and the calculated floating potentials become 8.702 kV and −5.849 kV, reflecting reductions of 84.8% and 88.4%, respectively. This research demonstrates that the proposed method provides an effective solution for floating potential calculation during single-circuit outages in double-circuit DC lines. The analysis of charge dissipation through voltage-limiting resistors offers technical support for designing DC de-icing devices.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"4 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cross-linking byproducts in the cross-linked polyethylene (XLPE) cable insulation material significantly affect the insulation properties of XLPE, and the non-destructive detection method for cross-linking byproducts during cable degassing process still faces great challenges. This work develops an extra-low frequency (ELF) dielectric analysis method based on time-dependent polarisation current for non-destructive detection of byproducts in XLPE. The effects of single byproduct of acetophenone and cumyl alcohol on the ELF dielectric properties of XLPE are studied separately. The ELF associated static permittivity and the dielectric loss of XLPE rise as the content of the single byproduct increases, and the α relaxation (10−4–10−3 Hz) and β relaxation (10−3–10−2 Hz) of XLPE are observed. Ionisation of acetophenone occurs above electric field strength of 20 kV, whereas ionisation tends to saturate above 50 kV. The optimal field strength for ELF dielectric testing of XLPE is determined to be 20–50 kV. Furthermore, the degassing factor is proposed to accurately determine the removal of byproducts. Based on these, the non-destructive detection of degassing of XLPE cable is achieved. The proposed ELF dielectric analysis method enables the non-destructive detection of byproducts in cables, opening a new avenue for cable degassing effect evaluation.
{"title":"The Extra-Low Frequency Dielectric Analysis Method for Evaluating Byproducts of Cross-Linked Polyethylene Cable Insulation Materials","authors":"Wenpeng Li, Shuxin Bi, Chong Zhang, Zhiyi Gao, Yang Zhou, Yingjian Liu, Weijia Zhao, Jinghui Gao, Lisheng Zhong","doi":"10.1049/hve2.70136","DOIUrl":"https://doi.org/10.1049/hve2.70136","url":null,"abstract":"Cross-linking byproducts in the cross-linked polyethylene (XLPE) cable insulation material significantly affect the insulation properties of XLPE, and the non-destructive detection method for cross-linking byproducts during cable degassing process still faces great challenges. This work develops an extra-low frequency (ELF) dielectric analysis method based on time-dependent polarisation current for non-destructive detection of byproducts in XLPE. The effects of single byproduct of acetophenone and cumyl alcohol on the ELF dielectric properties of XLPE are studied separately. The ELF associated static permittivity and the dielectric loss of XLPE rise as the content of the single byproduct increases, and the α relaxation (10<sup>−4</sup>–10<sup>−3</sup> Hz) and β relaxation (10<sup>−3</sup>–10<sup>−2</sup> Hz) of XLPE are observed. Ionisation of acetophenone occurs above electric field strength of 20 kV, whereas ionisation tends to saturate above 50 kV. The optimal field strength for ELF dielectric testing of XLPE is determined to be 20–50 kV. Furthermore, the degassing factor is proposed to accurately determine the removal of byproducts. Based on these, the non-destructive detection of degassing of XLPE cable is achieved. The proposed ELF dielectric analysis method enables the non-destructive detection of byproducts in cables, opening a new avenue for cable degassing effect evaluation.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"44 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ke Li, Luming Zhou, Guimin Jiang, Yunxiao Zhang, Yuanxiang Zhou
Dielectric degradation typically originates from local defects. The resulting electric field concentration accelerates defect growth. Suppressing field distortion arising from such local weaknesses has long been a major challenge in electrical insulation. In this work, we incorporated the voltage stabiliser anthrone (ET) into cross-linked polyethylene (XLPE). This design enables field-driven adaptive migration and charge trapping, thereby dynamically regulating local electric fields. Space charge analysis reveals that ET captures charge and creates a reverse electric field. This process inhibits charge injection and transport, significantly reduces internal field distortion and results in a negative electric field coefficient effect. Notably, at 110 kV/mm the distortion ratio decreases from 118.6% in XLPE to only 0.05% in ET/XLPE, a reduction by more than 2000 times. These findings highlight the critical role of voltage stabilisers in enhancing dielectric reliability.
{"title":"Significant Suppression of High Electric Field Regions in XLPE via Voltage Stabilisers","authors":"Ke Li, Luming Zhou, Guimin Jiang, Yunxiao Zhang, Yuanxiang Zhou","doi":"10.1049/hve2.70133","DOIUrl":"https://doi.org/10.1049/hve2.70133","url":null,"abstract":"Dielectric degradation typically originates from local defects. The resulting electric field concentration accelerates defect growth. Suppressing field distortion arising from such local weaknesses has long been a major challenge in electrical insulation. In this work, we incorporated the voltage stabiliser anthrone (ET) into cross-linked polyethylene (XLPE). This design enables field-driven adaptive migration and charge trapping, thereby dynamically regulating local electric fields. Space charge analysis reveals that ET captures charge and creates a reverse electric field. This process inhibits charge injection and transport, significantly reduces internal field distortion and results in a negative electric field coefficient effect. Notably, at 110 kV/mm the distortion ratio decreases from 118.6% in XLPE to only 0.05% in ET/XLPE, a reduction by more than 2000 times. These findings highlight the critical role of voltage stabilisers in enhancing dielectric reliability.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"18 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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