Assessment of the Withstand Ability to Short Circuit of Inner Windings in Power Transformers Considering the Degree of Thermal Aging

被引：0

作者：

Zhang F. ^{[1
]}

Li X. ^{[1
]}

Zhu X. ^{[1
]}

Zhuang Z. ^{[1
]}

Shi Y. ^{[2
]}

Ji S. ^{[1
]}

机构：

[1] State Key Laboratory of Electrical Insulation and Power Equipment (Xi'an Jiaotong University), Xi'an

[2] Electric Power Research Institute of State Grid Shaanxi Electric Power Co., Ltd., Xi'an

来源：

Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | 2022年 / 42卷 / 10期

基金：

中国国家自然科学基金; 中国博士后科学基金;

关键词：

Inner windings; Thermal aging; Transformer; Withstand ability to short circuits;

D O I：

10.13334/j.0258-8013.pcsee.211003

中图分类号：

学科分类号：

摘要：

During the service life of transformers, thermal stresses can change the mechanical properties of pressboards, and consequently change windings' withstand ability to short circuits (WASC). In this paper, the accelerated aging experiments were conducted firstly to obtain the mechanical properties of aging pressboards. Secondly, radial bending stresses and critical loads of inner windings were analyzed by establishing the finite element model, where the stiffness of stays was considered. Finally, the proposed model was used to evaluate the WASC of a 110 kV out-of-service power transformer, and short-circuit tests were carried out. The results show that the elastic modulus of pressboards drops with the increasing aging degree. Based on the proposed model, the radial bending stresses and the critical load are one-fifth and a quarter of the results calculated from the beam model and the two-hinged arch model, respectively. With the increasing degree of aging, the safety factor of radial bending stresses increases, while the safety factor of critical load decreases, indicating that the aged windings are easily to have buckling deformation. The conclusions can provide an important basis for evaluating the WASC of aging transformers. © 2022 Chin. Soc. for Elec. Eng.

引用

页码：3836 / 3845

页数：9

共 26 条

[1]

Transformer reliability survey, (2015)

[2]

LING Min, GU Zhengxiang, Nation-wide fault statistics and analysis of transformers from 1990 to 1994, Power System Technology, 20, 9, pp. 47-52, (1996)

[3]

WANG Mengyun, Statistic analysis of transformer's faults and defects at voltage 110kV and above, Distribution & Utilization, 24, 1, pp. 1-5, (2007)

[4]

LIU Zehong, LU Licheng, ZHOU Yuanxiang, Et al., Research on pressure characteristics of AC turret on arc fault, Proceedings of the CSEE, 41, 13, pp. 4688-4697, (2021)

[5]

DU Haoyang, CUI Lun, AO Ming, Et al., Design of de-noising algorithm for 3D imaging system of transformer winding ultrasonic testing, High Voltage Engineering, 46, 12, pp. 4376-4382, (2020)

[6]

JI Shengchang, ZHANG Fan, SHI Yuhang, Et al., Review on vibration-based mechanical condition monitoring in power transformers, High Voltage Engineering, 46, 1, pp. 257-272, (2020)

[7]

ZHANG Fan, JI Shengchang, SHI Yuhang, Et al., Research on transformer winding vibration and propagation characteristics, Proceedings of the CSEE, 38, 9, pp. 2790-2798, (2018)

[8]

ZHANG Bingqian, XIAN Richang, YU Yang, Et al., Analysis of physical characteristics of power transformer windings under inter-turn short circuit fault, High Voltage Engineering, 47, 6, pp. 2177-2185, (2021)

[9]

PAN Chao, Ge Jiarou, LIU Tianshu, Et al., The electromagnetic vibration characteristics of the first end of single-phase transformer, Electric Power Engineering Technology, 38, 6, pp. 147-153, (2019)

[10]

LIU Zhihua, CUI Yanjie, JI Shengchang, Et al., Influence of thermo-mechanical combined stress on insulation and mechanical characteristics of oil-impregnated paperboard, Electric Power Engineering Technology, 39, 5, pp. 126-132, (2020)

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