[FEMM] Finite Element Magnetic Model of the SRM2 Electric Synchronous Reluctance Motor being considered for the Hybrid Electric Vehicle Toyota Prius (2023)

Feel free to use this FEMM model as you wish. Below are some points that I had to assume in order to get the model running as close to the published data [1,2], as possible. If you find new improvements, feel free to adjust the model and share your findings with the rest of the community, possibly here via Figshare. I hope this is useful. Have fun !-----------------------------------------------------------------------------------------------------------------------------------------------------------<b>BEGINNER: </b>if you are just starting, and wish to access a simple step-by-step example of an electric motor modelled in FEMM, then I would recommend the following short thesis, before tackling the above simulation.<b>FEMM: </b>official homepage and open source software download is here. With it, you can open, modify and rerun the above FEMM files.<b>DESIGN: </b>the 2D drawing of the model was extracted (to the best of this authors ability) from the original publication [1] The DWG files are in enclosed, so you can make your own modifications. These were created with the open source software nanoCAD, however other free CAD softwares like FreeCAD can be used too.<b>ANGLES/CURRENTS:</b> The same model with various angles are provided here. To make your own angle, take the aligned case, select the arc curves by mouse right-click (they become red colored), and press in the top down menu <i>Edit &gt; move</i>. There select rotation (the default of 0,0 is correct) and type your angle (negative moves CW, and positive CCW). To alter the current i, go to the top down menu <i>Properties &gt; circuits</i>. Select R and press <i>modify</i>, followed by typing the new current. Do the same thing for B. Rerun the model, and you are done.<b>MATERIALS:</b> Not all of the required material properties of the Super Core 10JNEX900 necessary for the stator and rotor (like for instance the non-linear B-H curve) were available to program it into the FEMM, thus an alternative (lesser performant) steel was used (namely M-15 which was available in the FEMM material library). This possibly accounts for the fact that the predicted flux-linkage values are slightly lower (around on average 5%) than those originaly published in [1,2].<b>COILS: </b>As per this author's understanding, the experiment had each stator pole coiled with 17 parallel-connected wires (each with a diameter of d=0.6mm) with 22 turns (around the pole) each, stacked on top of each other. The approach used to model this in FEMM was to lump the 22 turns into a single turn of an equivalently larger diameter wire (D=sqrt(N)d=sqrt(22).0.6=3mm, having the same group crossectional area and thus transporting the same current ---- skinning effects are not considered here), and coil it 17 times around the pole. The Flux-Linkage (Wb) is extracted from the results (.ans file), by pressing the button that looks like a coil. The aforementioned short thesis presents an analytical way to compute the flux-linkage, based on the individual path of each magnetic circuit. If you wish to model a different coil length other than 135mm, then this can be altered in the top down menu <i>Problem (k</i>eep the name of the coil material short like <i>W x 22</i>, otherwise they overlap and become ilegible).<b>OBSERVATIONS:</b> In my experience, if (when you press the compute button) the error "Cannot compute" appears, it is almost always because you forgot a point not connected to a line, or an undefined source point somewhere, that only needs deletion for it to work (a recurrent problem comes when you press somewhere in the FEMM window as you transit from another window, and automatically leave a point on that spot that prevents the computation --- FEMM does not have a mouse pointer, and the default is the point creation/highlighting pointer. This has hapenned to me many times, and thus it may happen to you too). So, the error probably has nothing to do with the numerics, and does not necessarily mean that it will not compute, it simply means that you didn't tidy up your geometry (and it will not run until this is resolved). Problems with lines show in red are easy to see, but a missed point somewhere is harder to spot. Usually, if indeed the solver cannot compute, what you will see is the progress bar starting and getting stuck (either in the 2nd or 3rd bar of the first sweep), or the progress bar never moves (meaning that the solver got stuck somewhere in the mesh, trying to solve something it cannot compute like a numerical anomaly --- for instance, a singularity on a cell predicting infinite magnetic flux).[1] - Test Results and Torque Improvement of the 50-kW Switched Reluctance Motor Designed for Hybrid Electric Vehicles[2] - Average Rated Torque Calculations for Switched Reluctance Machines Based on Vector Analysis-------------------------------------------------------------------------For more public data, please visit my Figshare profile: https://figshare.com/authors/Luis_Teia/10811244您可自由使用本FEMM模型。下文为确保该模型尽可能贴合已发表文献[1,2]中的数据而做出的必要假设说明。若您发现可优化之处，可自行调整模型并将研究成果分享至社区，亦可通过Figshare平台发布。希望本模型对您有所助益，祝您使用愉快！ ----------------------------------------------------------------------------------------------------------------------------------------------------------- <b>BEGINNER: </b>若您刚接触该领域，并希望获取一个基于FEMM建模的电机分步实操示例，建议您在开展上述仿真前，先参考以下短篇学位论文。 <b>FEMM: </b>官方主页及开源软件下载链接见此处。通过该软件，您可打开、修改并重新运行上述FEMM模型文件。 <b>DESIGN: </b>本模型的二维绘图已尽可能由笔者从原始文献[1]中提取。随附的DWG格式文件可供您自行修改，这些绘图由开源软件nanoCAD创建，您亦可使用FreeCAD等其他免费CAD软件进行编辑。 <b>ANGLES/CURRENTS:</b> 本文提供了多种转子角度下的同款模型。若需自定义角度，可打开对齐状态的模型文件，右键单击选中圆弧曲线（此时曲线将变为红色），然后通过顶部菜单栏选择<i>Edit &gt; move</i>。在弹出的选项中选择旋转功能（默认原点(0,0)为旋转中心，符合需求），输入目标角度即可：负值对应顺时针旋转，正值对应逆时针旋转。若需修改电流i，可通过顶部菜单栏进入<i>Properties &gt; circuits</i>，选中绕组R并点击<i>modify</i>，输入新的电流数值即可；绕组B的修改流程与之相同。完成设置后重新运行模型，即可得到对应结果。 <b>MATERIALS:</b> 由于无法获取定子与转子所用的Super Core 10JNEX900的全部必要材料参数（例如非线性B-H曲线），无法将其直接导入FEMM中，因此选用了FEMM材料库中已有的M-15钢作为替代材料（该材料性能稍逊）。这一替换可能导致仿真得到的磁链数值较文献[1,2]中原始发表结果略低（平均降幅约5%）。 <b>COILS: </b>据笔者理解，原实验中每个定子极上绕有17组并联绕组，每组绕组包含22匝直径为0.6mm的导线，且各匝导线堆叠排布。为在FEMM中复现该绕组结构，我们将22匝导线等效为单匝大直径导线（等效直径D=√N·d=√22×0.6≈3mm，以保证总横截面积不变，进而保持总电流一致——本文未考虑集肤效应），再将该等效导线绕定子极17次。磁链（单位：韦伯Wb）可通过点击仿真结果（.ans文件）中形似线圈的按钮提取。前文提及的短篇学位论文提供了基于各磁路路径的磁链解析计算方法。若您需要修改绕组长度至135mm以外的数值，可通过顶部菜单栏<i>Problem</i>进行调整；请将绕组材料名称设置为类似<i>W x 22</i>的短名称，否则名称将重叠且无法辨认。 <b>OBSERVATIONS:</b> 根据笔者经验，若点击计算按钮后出现"Cannot compute"错误，几乎均是由于存在未与线段连接的孤立点，或某处存在未定义的源点，仅需删除该异常点即可解决问题。常见的触发场景为：从其他窗口切换至FEMM窗口时，误点击窗口内某位置，导致软件自动在该处生成一个孤立点，进而阻碍计算——FEMM无专用鼠标指针，默认指针即为点创建/高亮指针。该问题笔者曾多次遇到，因此您也可能碰到。此类错误与数值计算逻辑无关，也不代表仿真必然失败，仅表明您未完成几何模型的清理工作，需修复后方可运行。红色高亮的线段问题较易排查，但遗漏的孤立点则较难发现。若确实因求解器问题无法完成计算，您将看到进度条启动后停滞（通常卡在第一次扫描的第2或第3个进度条位置），或进度条完全无移动（表明求解器在网格划分或求解过程中陷入停滞，例如遇到数值异常——如单元内出现预测磁通量无穷大的奇点）。 [1] - 《面向混合动力汽车的50kW开关磁阻电机的试验结果与转矩提升优化》 [2] - 《基于矢量分析的开关磁阻电机额定平均转矩计算》 ------------------------------------------------------------------------- 如需获取更多公开数据集，请访问我的Figshare个人主页：https://figshare.com/authors/Luis_Teia/10811244