{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T01:29:24Z","timestamp":1789090164519,"version":"build-2803163510"},"reference-count":30,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T00:00:00Z","timestamp":1776816000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"\u201cTao Du Talent\u201d Science and Technology Innovation and Entrepreneurship Talent Team Project of Yixing City","award":["CX202104C"],"award-info":[{"award-number":["CX202104C"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Epoxy-glass-mica composite materials are widely used as electrical insulating materials in high-voltage rotating machinery due to their layered structure and excellent dielectric properties. Taking the F-class epoxy glass with a small amount of rubber powder mica tape commonly used as the main insulation of wind turbine stator coils as the research object, 7-day, 14-day, 21-day, and 28-day low-temperature treatment tests were conducted at \u221250 \u00b0C. The surface morphology and chemical structure changes of the materials were characterized by SEM and FTIR, and the influence laws of low-temperature treatment on the electrical properties of the mica tape insulation materials were systematically studied. The experimental results show that the low-temperature environment will induce microcracks and interface delamination and other structural damages, but no obvious change in the chemical structure of the mica tape was observed. With the extension of the low-temperature treatment time, the electrical properties of the mica tape show a deteriorating trend, and after 28 days of low-temperature treatment, the breakdown field strength of the F-class mica tape decreased by approximately 18.5%, and the volume conductivity overall increased by about two orders of magnitude. This indicates that the microcrack defects induced by low-temperature will lead to an enhanced electrical-thermal coupling effect in the insulation structure, thereby accelerating the degradation process of the insulation material. This reveals the degradation mechanism of wind turbine stator main insulation from \u201cstructural damage\u201d to \u201cperformance degradation\u201d and then to \u201cinsulation aging\u201d under low-temperature conditions, providing a theoretical basis for the design and reliability assessment of insulation systems in wind turbine generators in cold regions.<\/jats:p>","DOI":"10.3390\/ma19091675","type":"journal-article","created":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T09:01:24Z","timestamp":1776848484000},"page":"1675","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Effects of Prolonged Cryogenic Exposure on the Electrical Degradation of Stator Main Insulation in Wind Turbines"],"prefix":"10.3390","volume":"19","author":[{"given":"Zheng","family":"Dong","sequence":"first","affiliation":[{"name":"School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4387-5232","authenticated-orcid":false,"given":"Haitao","family":"Hu","sequence":"additional","affiliation":[{"name":"School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7652-2388","authenticated-orcid":false,"given":"Junguo","family":"Gao","sequence":"additional","affiliation":[{"name":"School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China"},{"name":"State Key laboratory of Electrical Insulation and Power Equipment, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mingpeng","family":"He","sequence":"additional","affiliation":[{"name":"Dongfang Electric Machinery Co., Ltd., Deyang 618000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhongyi","family":"Huang","sequence":"additional","affiliation":[{"name":"School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-3653-9571","authenticated-orcid":false,"given":"Yanli","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,22]]},"reference":[{"key":"ref_1","first-page":"41","article-title":"Study on Thinning the Main Insulation Thickness of Stator Windings in Hydroelectric Generators","volume":"4","author":"Liu","year":"2023","journal-title":"Shanghai Large Medium-Sized Electr. 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