摘要
随着特高压直流输电以及晶闸管整流设备的全面发展,电力系统谐波出现并流入变电站,使变电站中电力变压器出现非正常工作状态,影响其稳定运行.谐波注入使变压器铁心硅钢片的磁特性包括磁化特性和磁致伸缩特性畸变,由于变压器铁心振动主要来源于交变磁场下硅钢片的磁致伸缩,因此谐波下磁致伸缩特性畸变会直接导致变压器振动特性异常.然而,对于这种谐波激励下变压器的异常振动特性,目前未见相关报道.本文在考虑磁致伸缩效应和麦克斯韦电磁应力的基础上,研究谐波入侵对变压器振动特性的影响.首先对叠加不同3次谐波磁场下取向硅钢片样片的磁化特性以及磁致伸缩特性进行测试;然后,根据测试数据建立单相变压器三维磁-机械耦合数值模型并进行空载下变压器振动仿真;根据仿真结果,分析谐波对变压器铁心应力分布、振动加速度及其频谱的影响,为分析变压器在谐波工况下振动特性奠定理论基础.
With development of the uhra-high voltage DC transmission system and the thyristor rectifier equipment in high voltage distribution network, theharmonic in power system is injected into transformer substation, which will lead to the abnormal operating of transformer. Transformer core is assembled by silicon-steel lamination. The silicon steel pro- duces regular deformation due to the magnetostriction effect in an alternating magnetic field. Meanwhile, the magnetic and magnetostrictive characteristics of silicon steel will distort when harmonic vohages are applied to the transformer windings, which will influence the transformer vibration. However, the vibration characteristic of transformer under harmonic excita- tion has not been reported. This paper studies the influence of harmonic on the transformer vibration by considering Maxwell electromagnetic force and magnetostriction effect. Firstly, magnetic and magnetostrietive characteristic curves are tested when excitation magnetic source is superposed with different the third harmonics. Then, a three-dimensional mag- neto-mechanical coupled model of transformer is presented. The influence of the third harmonic on core stress distribution, vibration acceleration curves and frequency spectrum are analyzed, which can help lay the theoretical basis on the study of transformer vibration under different harmonic excitations.
作者
贲彤
杨庆新
闫荣格
祝丽花
BEN Tong YANG Qingxin YAN Rongge ZHU Lihua(Province-Ministry Joint Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability, Hebei University of Technology, Tianjin, 300130,China Tianjin Key Laboratory of Advanced Technology of Electrical Engineering and Energy, Tianjin Polytechnic University, Tianjin 300387, China)
出处
《河北工业大学学报》
CAS
2017年第3期1-7,17,共8页
Journal of Hebei University of Technology
基金
国家自然科学基金重点项目(51237005)
国家自然科学基金(51507110
51177038)
关键词
谐波
磁-机械耦合数值模型
变压器铁心振动
变压器铁心应力分布
磁致伸缩
harmonic
magneto-mechanical strongly coupled model
transformer core vibration
stress distribution of transformer core
magnetostriction
