摘要
为明确纳米晶合金高频磁损耗与其微观结构的关系,基于随机各向异性理论,建立了介观尺度下纳米晶合金的三维模型。以晶体相体积分数V和晶粒尺寸d为研究参数,从介观层面探究了微观结构的变化对高频磁损耗pv的影响,并得出材料pv与V和d的函数关系式。结果表明:材料pv会随着V和d的增加而增加,且d对于材料pv的影响更为显著。当外部磁场频率保持10 kHz不变、V从60%增大为80%时,材料pv增长率为27.11%;相应地,d从6 nm增大到15 nm时,材料pv增长率为51.83%。从三者之间的函数关系式也可看出,晶粒尺寸d和体积分数V都与高频磁损耗pv正相关,但两者的指数系数却不相同,d的指数系数大于V的指数系数,因此,d的变化对于材料pv的影响更为显著。
With the continuous development of long distance DC power transmission and energy storage system in China,High Frequency Transformer which can realize DC voltage transformation through high power electronic devices and their control technology has been gradually applied.However,as the working frequency gradually increases to kilohertz,the core loss will increase greatly under the complex magnetic field at high frequency,and higher requirements are put forward for the performance of the core materials used in High Frequency Transformer.Nanocrystalline alloy is a kind of composite bipolar ferromagnetic material,not only has high saturation magnetic induction intensity,high effective magnetic permeability,low loss and low coercivity excellent soft magnetic properties,and low cost,simple preparation,high heat resistance,has widely used in high frequency ferromagnetic material.In order to clarify the relationship between high-frequency magnetic loss and internal microstructure of nanocrystalline alloy,a three-dimensional model of nanocrystalline alloy at mesoscopic scale was established based on G.Herzer's random anisotropy theory.Then,based on the ring sample method,an AC test system was constructed to measure the magnetic loss of nanocrystalline alloy with the volume fraction V=60%and the grain size d=10nm under alternating magnetic field excitation with amplitude H=0.7 T and frequency f=10 kHz.Next,to obtain magnetic loss of the model,a sinusoidal alternating magnetic field with the same amplitude and frequency was applied to the model.And the above two loss values are compared to verify the correctness of the model.Finally taking crystal phase volume fraction V and grain size d as research parameters,the influence of microstructure change on high frequency magnetic loss was investigated from the mesoscopic level,and the functional relationship between high frequency magnetic loss and volume fraction V and grain size d was obtained.The results show that the high frequency magnetic loss increases with the increase of volume fraction V and grain size d.This is because the high frequency loss of the material is mainly composed of eddy current loss.And the eddy current loss of the material is positively correlated with volume fraction V and grain size d,so when V and d increases,the high frequency loss of the material will increase.Meanwhile,the resistivity of the material will also increase with the increase of V and d,and the eddy current loss is inversely proportional to the resistivity of the material.Therefore,the eddy current loss of the nanocrystalline alloy will increase with the increase of V and d.Among them,grain size d has a more significant effect on high frequency loss of materials.When the external magnetic field frequency f remains constant(10 kHz)and the volume fraction V increases from 60%to 80%,the increase rate of high frequency magnetic loss is 27.11%.Accordingly,when the grain size d increases from 6 nm to 15 nm,the increase rate of high frequency loss is 51.83%.As can be seen from the functional relations among the three,both grain size d and volume fraction V are positively correlated with eddy current loss,but their coefficients are different.The coefficient of grain size d is larger than that of volume fraction V.Therefore,the change of grain size d has a more significant impact on the high frequency loss of materials.
作者
代岭均
邹亮
郭凯航
张黎
李永建
孙秋霞
Dai Lingjun;Zou Liang;Guo Kaihang;Zhang Li;Li Yongjian;Sun Qiuxia(School of Electrical Engineering Shandong University,Jinan 250061 China;Dalian Power Supply Company of State Grid Liaoning Electric Power Company,Dalian 116001 China;Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province Hebei University of Technology,Tianjin 300130 China;Shandong Taikai Transformer Co.Ltd,Taian 271000 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2023年第18期4853-4863,共11页
Transactions of China Electrotechnical Society
基金
国家自然科学基金项目(51977122,51307102)
省部共建电工装备可靠性与智能化国家重点实验室立项(EERI_KF2021011)资助。
关键词
纳米晶合金
晶粒尺寸
体积分数
高频磁损耗
Nanocrystalline alloy
grain size
volume fraction
high-frequency magnetic loss
