|
|
Equivalent Vector Magnetic Circuit Analysis of Transformer and Induction Motor Based on the Magductance |
Cheng Ming, Ma Zhengzhou, Wang Zheng, Qin Wei Hua Wei |
School of Electrical Engineering Southeast University Nanjing 210096 China |
|
|
Abstract The analysis of the working principle of transformers and induction motors mainly employs the equivalent electrical circuit in the traditional electrical machine theory. This approach represents actual magnetic quantities as electrical quantities, adding complexity to analysis. The traditional magnetic circuit theory, which only has reluctance elements, fails to characterize the phase differences between flux and magnetomotive force or iron losses, becoming a bottleneck. This paper introduces a novel magnetic parameter called magductance. By vector magnetic circuit theory, an equivalent vector magnetic circuit is established and applicable to transformer and induction motor analysis. Firstly, the equivalent magnetic circuit for different working conditions is derived. At no-load conditions, the core loss is expressed in terms of magductance L0. The phase difference between flux and magnetomotive force corresponds to the iron loss angle. The effect of the secondary side can be reflected through magductance L2. When the load is zero, the expression for magductance is based on the original definition. The phasor diagram of the transformer derived from equivalent vector magnetic circuit takes magnetic flux Φm as the common reference phasor, and links among the primaryside, secondary side, and core are directly expressed by magnetic quantity. Secondly, the equivalent vector magnetic circuit for the induction motor is derived. It adds the airgap reluctance Rg, and the rotor squirrel cage is equivalent to the magductance L2. Finally, the equivalent vector magnetic circuits for the transformer and induction motor are analyzed. (1) Vector magnetic circuit comprises reluctance R, equivalent magductance of core lossL0, and equivalent magductance of secondary side (the rotor squirrel cage in the induction motor) L2. (2) Loads of the transformer and induction motor can be directly considered in the equivalent magductance L2. (3) For the transformer, R is equal to core reluctance RFe, and there is R=RFe+2Rg in the induction motor. (4) Electrical frequency ω is the excitation electrical frequency of primary winding in the transformer, and electrical frequency sω is the slip frequency of the rotor relative to the magnetic field in the induction motor. Experimental measurements agree well with the calculated results of the transformer and induction motor. Compared with the existing equivalent electrical circuit, the proposed equivalent vector magnetic circuit saves the necessary turns referring and frequency referring. It characterizes the effect of L0 on the magnetic flux and phase difference and calculates their output performance, providing a novel and intuitive method for analyzing, designing, and controlling electromagnetic equipment.
|
Received: 10 August 2023
|
|
|
|
|
[1] 吴大榕. 电机学-上册[M]. 北京: 水利电力出版社, 1959. [2] 章名涛. 电机学-下册[M]. 北京: 科学出版社, 1964. [3] 许实章. 电机学[M]. 北京: 机械工业出版社, 1980-1981. [4] 周鹗. 电机学[M]. 3版. 北京: 中国电力出版社, 1995. [5] 胡虔生, 胡敏强. 电机学[M]. 北京: 中国电力出版社, 2005. [6] 汤蕴璆. 电机学[M]. 4版. 北京: 机械工业出版社, 2011. [7] Smolensky A I.Electrical Machines[M]. Moscow: MIR Publishers, 1982. [8] Fitzgerald A E, Kingsley C, Umans S D.Electric Machinery[M]. 6th ed. New York: McGraw-Hill Companies, 2003. [9] Joule J P.The Scientific Papers of James Prescott Joule[M]. Cambridge: Cambridge University Press, 1884. [10] Heaviside O.Electrical Papers[M]. Cambridge: Cambridge University Press, 2011. [11] Miller J D.Rowland’s magnetic analogy to Ohm’s law[J]. Isis, 1975, 66(2): 230-241. [12] Hopkinson J. Magnetisation of iron[J]. Philosophical Transactions of the Royal Society of London, 1885, 176: 455-469. [13] 程明, 周鹗, 黄秀留. 双凸极变速永磁电机的变结构等效磁路模型[J]. 中国电机工程学报, 2001, 21(5): 23-28. Cheng Ming, Zhou E, Huang Xiuliu.Variable structure equivalent magnetic circuit modeling for doubly salient permanent magnet machine[J]. Pro- ceedings of the CSEE, 2001, 21(5): 23-28. [14] 张淦, 花为, 程明, 等. 磁通切换型永磁电机非线性磁网络分析[J]. 电工技术学报, 2015, 30(2): 34-42. Zhang Gan, Hua Wei, Cheng Ming, et al.Analysis of nonlinear magnetic network models for flux- switching permanent magnet machines[J]. Transa- ctions of China Electrotechnical Society, 2015, 30(2): 34-42. [15] 庞古才, 邓智泉, 张忠明. 基于改进广义磁路法的表贴式永磁电机空载气隙磁场解析计算[J]. 电工技术学报, 2019, 34(22): 4623-4633. Pang Gucai, Deng Zhiquan, Zhang Zhongming.Analytical calculation of no-load air gap magnetic field in surface-mounted permanent magnet motor based on improved generalized magnetic circuit method[J]. Transactions of China Electrotechnical Society, 2019, 34(22): 4623-4633. [16] 郭凯凯, 郭有光. 磁通反向直线旋转永磁电机三维非线性等效磁路模型分析[J]. 电工技术学报, 2020, 35(20): 4278-4286. Guo Kaikai, Guo Youguang.3D nonlinear equivalent magnetic circuit model analysis of a flux reversal linear rotary permanent magnet machine[J]. Transa- ctions of China Electrotechnical Society, 2020, 35(20): 4278-4286. [17] 张志弘, 韩勤锴, 徐学平, 等. 基于保角变换与等效磁路法的永磁直驱发电机气隙磁场计算[J]. 电工技术学报, 2023, 38(3): 703-711. Zhang Zhihong, Han Qinkai, Xu Xueping, et al.Air gap magnetic field calculation of permanent magnet direct drive generator based on conformal mapping and magnetic equivalent circuit method[J]. Transa- ctions of China Electrotechnical Society, 2023, 38(3): 703-711. [18] 佟文明, 王萍, 吴胜男, 等. 基于三维等效磁网络模型的混合励磁同步电机电磁特性分析[J]. 电工技术学报, 2023, 38(3): 692-702. Tong Wenming, Wang Ping, Wu Shengnan, et al.Electromagnetic performance analysis of a hybrid excitation synchronous machine based on 3D equivalent magnetic network[J]. Transactions of China Elec- trotechnical Society, 2023, 38(3): 692-702. [19] 罗玲, 侯红胜, 宋受俊. 中美英三国“电机学”课程体系的分析[J]. 电气电子教学学报, 2013, 35(2): 33-35. Luo Ling, Hou Hongsheng, Song Shoujun.Analysis of the syllabus of electrical machinery in China, America and Britain[J]. Journal of Electrical & Electronic Education, 2013, 35(2): 33-35. [20] 谢宝昌, 刘长红, 王君艳, 等. “电机学”课程体系的优化[J]. 电气电子教学学报, 2011, 33(4): 18-20. Xie Baochang, Liu Changhong, Wang Junyan, et al.Systematic optimization of electric machinery curriculum[J]. Journal of Electrical & Electronic Education, 2011, 33(4): 18-20. [21] 曾令全, 李书权. “电机学”精品课建设及教学改革与实践[J]. 中国电力教育, 2013(27): 99-100. [22] 秦海鸿, 王晓琳, 黄文新, 等. “电机学”课程教学改革研究[J]. 电气电子教学学报, 2014, 36(4): 36-38. Qin Haihong, Wang Xiaolin, Huang Wenxin, et al.Research on the teaching reform of electric machines course[J]. Journal of Electrical & Electronic Education, 2014, 36(4): 36-38. [23] 叶才勇. 新工科背景下《电机学》教材改革探析[J]. 学园, 2020, 13(7): 88-89. [24] Laithwaite E R.Magnetic equivalent circuits for electrical machines[J]. Proceedings of the Institution of Electrical Engineers, 1967, 114(11): 1805. [25] Carpenter C J.Magnetic equivalent circuits[J]. Pro- ceedings of the Institution of Electrical Engineers, 1968, 115(10): 1503-1511. [26] Buntenbach R W.Improved circuit models for inductors wound on dissipative magnetic cores[C]// 2nd Asimolar Conference on Circuits and Systems, 1968. [27] 国家技术监督局. 电学和磁学的量和单位: GB/T 3102.5-1993[S]. 北京: 中国标准出版社, 1994. [28] Quantities andunits-part 6: electromagnetism: IEC 8000-6[S]. Geneva: IEC, 2022. [29] Cheng Ming, Qin Wei, Zhu Xinkai, et al.Magnetic- inductance: concept, definition, and applications[J]. IEEE Transactions on Power Electronics, 2022, 37(10): 12406-12414. [30] 秦伟, 程明, 王政, 等. 矢量磁路理论及应用初探[J/OL]. 中国电机工程学报, 2023: 1-14 [2023-11-07]. DOI: 10.13334/j. 0258-8013.pcsee.232113. Qin Wei, Cheng Ming, Wang Zheng, et al. Vector magnetic circuit theory and its preliminary applications[J/OL]. Proceedings of the CSEE, 2023: 1-14 [2023-11-07]. DOI: 10.13334/j.0258-8013.pcsee. 232113. [31] 程明, 秦伟, 朱新凯, 等. 楞次定律的定量化表征[EB/OL]. 中国科技论文在线[2022-07-21]. http:// www.paper.edu.cn/releasepaper/content/2022-07-21. [32] Qin Wei, Cheng Ming, Zhu Sa, et al.Reluctance and magductance calculation of laminated core under different frequency for electrical machines[C]//2022 25th International Conference on Electrical Machines and Systems (ICEMS), Chiang Mai, Thailand, 2022: 1-6. [33] Qin Wei, Cheng Ming, Wang Jingxia, et al.Com- patibility analysis among vector magnetic circuit theory, electrical circuit theory, and electromagnetic field theory[J]. IEEE Access, 2023, 11: 113008-113016. [34] 陈世坤. 电机设计[M]. 2版. 北京: 机械工业出版社, 2013. |
|
|
|