Maxwell 3d中的Eddy effect 警告要不要紧？
在maxwell 3d中会遇到这样的警告：
Eddy effect settings may need revisiting due to the recent changes in the design. The default value will be used for the object if the value is not specified. 问：这个警告要不要紧？
答：不要紧，默认设置为不考虑涡流。只是提醒一下。
Maxwell中的各种损耗power loss, core loss, ohmic loss, joule loss含义？
这里只有文字部分，图片请看http://forum.simwe.com/thread-861209-1-1.html
Losses mentioned in Maxwell includes, 1. Power loss 2. Core loss
3. Ohmic power loss (Joule loss)
*Note: this content is restricted to transient magnetic analysis. Power loss Definition: Any occasion that involves induced eddy current.
? laminated rotor and stator in PM motor has no power loss except laminations are modeled (this is almost impossible because the thin and big steel sheet needs incredible number of FEA elements)
? in most cases, eddy current effect in the sleeves holding the magnets in PM motor is considered, so there is power loss for the sleeve
? although it is not very common to calculate eddy current in other auxiliary parts, but if there are some objects where it is necessary to do so, power loss will be generated
? magnets in PM motor has power loss if eddy current effect is considered ? rotor bars in induction motor has power loss because of the eddy current ? stranded coils will have power loss if the stranded is actually modeled like the one shown below. This is unusual for motor.
? stranded coils have no power loss if not modeling every single strand (paraphrase of the previous statement) Core loss Definition: For laminated steel, 3 kinds of losses are considered. They are hysteresis loss, classical eddy current loss and excess loss. These losses are calculated by using the coefficients (Kh, Kc, Ke) derived from the loss graph provided by steel company. ? laminated rotor and stator in PM motor has core loss. Currently, this is the only way to calculate stator loss and rotor loss. OhmicLoss
Definition: This is the power loss density.
If there is more than one object involved in power loss calculation, the result power loss is the total. You can use the calculator in the post processor to integrate power loss density on specific volumes/areas to get the power loss in them.
Maxwellv12中徒手画图形还是用对话框画？
v12中徒手画还是用对话框画图形是可以选择的，用F3/F4在两种模式下切换。 不懂请看图：http://www.simol.cn/thread-18135-1-1.html
非常有用:铝铜等金属电阻率电导率随温度变化公式系数
此篇文章为转载，原文为英文，链接：http://www.ndt-ed.org/EducationResources/CommunityCollege/Materials/Physical_Chemical/Electrical.htm
我挑主要的内容说一下：
在2个温度下，电阻和电阻率的关系如下：R1 = R2 * [1 + a * (T1–T2)] 其中的温度系数a请按原文中表（本文最后）查询： 举例： 问题：25oC电阻率是2.706 x 10-8 a = 0.0043/ oC，请问20 oC时的电阻率是多少?
答案：R1 = R2 * [1 + a * (T1–T2)]
把下列参数带入上式：
R2 = 2.706 x 10-8 ohm meters (measured resistivity at 25 oC) a = 0.0043/ oC T1 = 20 oC T2 = 25 oC
得到：R1 = 2.706 x 10-8ohm meters * [1 + 0.0043/ oC * (20 oC – 25 oC)] = 2.648 x 10-8ohm meters
可以看出，温度越低，电阻率也就越低。或者说，温度越高，导体的导电性就越差，电阻就越大，通过相同电流时，损耗（一般导线材料是铜，因此也叫铜损）也就越大，这是在很多涉及到导线的设计时都需要考虑的问题。
Material Nickel Iron Molybdenum Tungsten Aluminum Copper Silver Platinum Gold Zinc Temperature Coefficient (/ oC) 0.0059 0.0060 0.0046 0.0044 0.0043 0.0040 0.0038 0.0038 0.0037 0.0038 maxwell中coil和winding有什么区别和联系？
coil和winding都是指线圈，但是ANSOFT用来设置不同的参数。
coil是用于设置电流方向，线圈数；而winding是用于设置激励源的种类（如：电流或者是电压），外加电阻（可选），外加电感（可选），激励源的数值或函数等等。
coil和winding的区别很多。
首先还是静态、涡流、瞬态的问题，只有瞬态有winding
瞬态时，只有在winding中才能设置使用内置变量如位置的函数，在coil中不能这样做。
其次，它们的意义也有区别。 winding相当于小组，coil相当于组员，一般是把A相定义为一个winding（小组），把A相的所有coil都加上去，B和C相同理。加的方法有两种，简单的一次选多个，复杂的一次选一个。
第三，并联支路数在winding中体现。coil没办法体现这个。