变压器硅钢片磁性能与磁屏蔽模型的铁损研究
发布时间：2019-06-12 10:09
【摘要】：大型电力变压器中结构件的杂散损耗主要由漏磁场及其分布决定，分布集中的漏磁场会引起局部过热，导致绝缘材料热老化等问题，，从而影响变压器运行的可靠性和寿命。为降低漏磁通所引起的损耗和温升，在变压器油箱、铁心拉板等金属部件上会广泛分布磁、电屏蔽。普遍应用的磁屏蔽和电磁屏蔽均采用高导磁性能的取向硅钢片叠积而成，故对其硅钢片材料的电磁性能研究尤为重要。 本文首先研究了磁屏蔽材料，即硅钢片的磁性能。通过对硅钢试片进行爱泼斯坦方圈磁性能测量实验，考察了等效磁路长度的影响因素（频率，取样角度，环境温度）。由三维仿真计算，证明了双爱泼斯坦方圈法的前提条件。为考虑其各部分对等效磁路长度的影响，提出了三方圈一级加权方法和二级加权处理法，确定25cm爱泼斯坦方圈的有效磁路长度，设计了功率分析仪WT3000和爱泼斯坦方圈组合测量激磁功率的实验，并测量了不同平均磁密、取样角度，不同的频率、环境温度的比总损耗及激磁功率。通过与双方圈法的比较分析结果，体现出其优越性。实验结果与分析结论对进一步研究大型电力变压器铁心与磁屏蔽的磁性能具有工业应用价值。 其次，针对硅钢片材料的应用，即磁屏蔽进行考察研究。然而屏蔽损耗难于直接测得，故需从所测得总损耗中将其分离出来。本文介绍了镜像测量方法，可将漏磁通进行补偿，以便能够有效分离磁屏蔽的损耗，将镜像模型进行二维建模与仿真分析，验证镜像测量法的合理性。根据保定天威集团电工技术研发中心进行改进的变压器产品模型屏蔽损耗与磁密测量的实验平台，共进行了针对五种模型的实验（立式磁屏蔽，平板式磁屏蔽，立式磁屏蔽与导磁钢板组合模型，平板式磁屏蔽与导磁钢板组合模型及电屏蔽与导磁钢板组合模型）。 最后，用电磁场分析软件MagNet V7.2对其进行三维建模和仿真，将激励绕组进行均匀化处理，并考虑硅钢片的磁各向异性与非线性，在不同激励工况下，将模型的磁密与损耗详细对比分析并进行有效的基准化模型实验验证，为实际产品应用提供了一定的参考价值。
[Abstract]:The stray loss of structural parts in large power transformers is mainly determined by the leakage magnetic field and its distribution. The concentrated leakage magnetic field will cause local overheating and lead to thermal aging of insulation materials, thus affecting the reliability and life of transformer operation. In order to reduce the loss and temperature rise caused by magnetic flux leakage, magnetic and electric shielding will be widely distributed in transformer fuel tank, iron core drawing plate and other metal parts. Both magnetic shielding and electromagnetic shielding are composed of oriented silicon steel sheets with high magnetic conductivity, so it is particularly important to study the electromagnetic properties of silicon steel sheet materials. In this paper, the magnetic properties of magnetic shielding material, that is, silicon steel sheet, are studied. The factors affecting the length of equivalent magnetic circuit (frequency, sampling angle, ambient temperature) were investigated by measuring the magnetic properties of Epstein square ring on silicon steel specimen. The precondition of double Epstein square circle method is proved by three dimensional simulation. In order to consider the influence of each part on the equivalent magnetic circuit length, the first-order weighting method and the second-order weighted processing method of the three-square ring are proposed to determine the effective magnetic circuit length of the 25cm Epstein square loop. The experiment of measuring the excitation power by the combination of the power analyzer WT3000 and the Epstein square ring is designed, and the specific total loss and excitation power of different average magnetic density, sampling angle, different frequency, environmental temperature and magnetic power are measured. Through the comparison and analysis with the double circle method, it shows its superiority. The experimental results and analysis results are of industrial application value for the further study of the magnetic energy of core and magnetic shield of large power transformers. Secondly, the application of silicon steel sheet material, that is, magnetic shielding, is investigated and studied. However, the shielding loss is difficult to be measured directly, so it needs to be separated from the measured total loss. In this paper, the mirror image measurement method is introduced, which can compensate the magnetic leakage flux so that the loss of magnetic shield can be separated effectively. The mirror model is modeled and simulated in two dimensions to verify the rationality of the mirror image measurement method. According to the improved experimental platform of transformer product model shielding loss and magnetic density measurement carried out by Baoding Tianwei Group Electrical Technology Research and Development Center, a total of experiments were carried out for five models (vertical magnetic shielding, flat plate magnetic shielding, vertical magnetic shielding and magnetic conductive plate combination model, flat plate magnetic shielding and magnetic conductive plate combination model and electric shielding and magnetic conductive steel plate combination model). Finally, the three-dimensional modeling and simulation of the electric magnetic field analysis software MagNet V7.2 is carried out, the excitation winding is homogenized, and the magnetic anisotropy and nonlinear of silicon steel sheet are considered. under different excitation conditions, the magnetic density and loss of the model are compared and analyzed in detail and verified by effective reference model experiments, which provides a certain reference value for the application of practical products.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM41;TM275
本文编号：2497931
[Abstract]:The stray loss of structural parts in large power transformers is mainly determined by the leakage magnetic field and its distribution. The concentrated leakage magnetic field will cause local overheating and lead to thermal aging of insulation materials, thus affecting the reliability and life of transformer operation. In order to reduce the loss and temperature rise caused by magnetic flux leakage, magnetic and electric shielding will be widely distributed in transformer fuel tank, iron core drawing plate and other metal parts. Both magnetic shielding and electromagnetic shielding are composed of oriented silicon steel sheets with high magnetic conductivity, so it is particularly important to study the electromagnetic properties of silicon steel sheet materials. In this paper, the magnetic properties of magnetic shielding material, that is, silicon steel sheet, are studied. The factors affecting the length of equivalent magnetic circuit (frequency, sampling angle, ambient temperature) were investigated by measuring the magnetic properties of Epstein square ring on silicon steel specimen. The precondition of double Epstein square circle method is proved by three dimensional simulation. In order to consider the influence of each part on the equivalent magnetic circuit length, the first-order weighting method and the second-order weighted processing method of the three-square ring are proposed to determine the effective magnetic circuit length of the 25cm Epstein square loop. The experiment of measuring the excitation power by the combination of the power analyzer WT3000 and the Epstein square ring is designed, and the specific total loss and excitation power of different average magnetic density, sampling angle, different frequency, environmental temperature and magnetic power are measured. Through the comparison and analysis with the double circle method, it shows its superiority. The experimental results and analysis results are of industrial application value for the further study of the magnetic energy of core and magnetic shield of large power transformers. Secondly, the application of silicon steel sheet material, that is, magnetic shielding, is investigated and studied. However, the shielding loss is difficult to be measured directly, so it needs to be separated from the measured total loss. In this paper, the mirror image measurement method is introduced, which can compensate the magnetic leakage flux so that the loss of magnetic shield can be separated effectively. The mirror model is modeled and simulated in two dimensions to verify the rationality of the mirror image measurement method. According to the improved experimental platform of transformer product model shielding loss and magnetic density measurement carried out by Baoding Tianwei Group Electrical Technology Research and Development Center, a total of experiments were carried out for five models (vertical magnetic shielding, flat plate magnetic shielding, vertical magnetic shielding and magnetic conductive plate combination model, flat plate magnetic shielding and magnetic conductive plate combination model and electric shielding and magnetic conductive steel plate combination model). Finally, the three-dimensional modeling and simulation of the electric magnetic field analysis software MagNet V7.2 is carried out, the excitation winding is homogenized, and the magnetic anisotropy and nonlinear of silicon steel sheet are considered. under different excitation conditions, the magnetic density and loss of the model are compared and analyzed in detail and verified by effective reference model experiments, which provides a certain reference value for the application of practical products.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM41;TM275
【参考文献】
相关期刊论文 前1条
1 程志光,高生,胡启凡,刘志光,吴明训,刘玉仙;钢中涡流和磁滞损耗问题[J];变压器;1999年09期
本文编号：2497931
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