ansoft13的损耗计算和后处理问题

kt266a

我接触ansoft12和13的时间短。很多事情在ansys里面容易做到的，在ansoft里面不明白了。

大概有以下的疑问：
以ansoft12和13为例

1、coreloss毫无疑问是设置过铁耗曲线的磁性材料的铁损，包括涡流、磁滞、附加损耗。

2、场计算器中只有ohmicloss和totalloss，指的是什么？
我看了ansoft13说明文件，自己还不敢下定论。大家一起讨论一下。

Loss Quantities


Ohmic
loss
Ohmic loss is always associated with conduction current distribution in conductors which are not perfect. Thus the resistivity of conductors is responsible for the ohmic power loss when current flows in such conductors. It is also called the Joule-Lenz effect. There is always a heating effect due to the ohmic loss, often called Joule heating.

Total loss
Total loss is associated with loss density fields in 3D magnetic transient solutions. Total loss uses the total integrated loss output from the solver and averages it over two consecutive times.

Hysteresis
loss
Hysteresis loss is short for magnetic hysteresis loss and represents power loss in some magnetic materials (electric steels or ferrites) in alternating (sinusoidal) magnetic fields. This loss is due to a phenomenon called "magnetic viscosity" which causes the B and H fields to have a phase shift between them. In the B-H plane, for linear materials, the relationship between these two fields describes an ellipse. The hysteresis loss is proportional to the area of the ellipse.

Dielectric
loss
Dielectric loss or electric hysteresis loss represents power loss in ferroelectric materials (such as barium titanate, lead zirconate titanate ) in alternating (sinusoidal) electric fields. This loss is due to a phenomenon called "electric viscosity" which causes the D and E fields to have a phase shift between them. In the D-E plane, for linear materials, the relationship between these two fields describes an ellipse. The dielectric loss is proportional to the area of the ellipse.

SurfaceLoss
Density
The surface loss density is assocaited with the induced eddy current on the impedence bounday.

Emloss
(2D Eddy)
In 2D eddy emloss combines the ohmic loss, dielectric loss and hysteresis loss.

Edgeloss
density
Edge loss density represents losses associated with impedance boundary applied on conductive surfaces on the boundary of the solution domain or on surface of excluded objects. It assumes an exponential spatial decay (towards the interior of the respective material) of induced current magnitudes and of associated losses. Integrating the loss along the edge produces the entire loss associated with the "edge".

Core
loss
The core loss combines eddy current losses and hysteresis losses for a transient solution type. It is a post-processing calculation, based on already calculated transient magnetic field quantities. It is applicable for the evaluation of core losses in steel laminations (frequently used in applications such as electric machines, transformers) or in power ferrites.

Solid
Loss
The solid loss represents the resistive loss in a 2D or 3D volume and is calculated by:



For 2DXY designs, the length is given by Set Model Depth, while for RZ designs the volume is based upon the rotation of the cross section around the symmetry axis.

Stranded
Loss
The stranded loss represents the resistive loss in a 2D or 3D volume and is calculated by:



where J is the conductivity of the material. Note that the stranded loss calculation does not use the INPUT resistance value R that is assigned in the winding setup. If you expect the stranded loss to correspond to the lumped INPUT resistance value R, use the following procedure to compute the effective conductivity of the material:

1. Make a copy of the design. In the copy, change the winding to a stranded current winding, and set the current to a constant 1A. You can reduce the stop-time so that only a couple of time steps are solved.

2. Solve the copied design and examine the stranded loss. It should be constant with respect to time. Because the current was set to 1A, the derived stranded loss quantitatively is the corresponding FIELD stranded resistance associated with the original input conductivity of the material.

3. Determine the effective conductivity, which corresponds to the lumped INPUT resistance R, by multiplying the original conductivity of the material by the ratio of the FIELD resistance to the desired INPUT resistance of the winding.

4. Modify the material property in the original design with this new conductivity value, which corresponds to the lumped INPUT resistance R.

kt266a

问题是
在三维瞬态计算中
1、设置了铁耗曲线的叠片铁心，损耗是totalloss ？
2、设置了电导率的线棒（绞线类型，外加交流电，不考虑涡流），损耗是？
3、设置了电导率的solid类型的结构件（无外加电流，但是考虑涡流），损耗是？

为了计算损耗比较准确一些，网格剖分和时间步长应该怎么设置？

kt266a

另外，后处理环节还有一些疑问
1、ansoft场计算器能不能输入柱坐标系的坐标值？
2、可不可以指定坐标范围对损耗密度做体积分
3、可不可以在场计算器直接把多个体相加，求它们的损耗之和
4、怎么对某个节点一段时间（也就是多个时刻）的损耗密度做积分（也就是相加）？或者是对某个体的多个时刻的损耗相加？
5、我知道在旧版ansoft里面有信号计算器（the Signal Calculator）可以做对曲线的采样和积分。问题是ansoft12或13怎么办？

几位高手讨论过信号计算器，在此感谢他们的贡献精神。
帖子：http://bbs.simol.cn/viewthread.p ... hlight=%CB%F0%BA%C4
http://bbs.simol.cn/thread-28604-1-1.html

kt266a

HENGKOU 前辈发表过一些。我转载一下。

Full Load Current

Return to PlotData to analyze the full load current.

➤  Analyze the full load current:
   1.  Open the extnl_i.dat plot. This plot represents the current measured in the external circuit you
       created in Schematic Capture. Using the Plot Data calculator, you can calculate the average line
       current value directly.
   2.  Choose Tools/Calculator to access the Signal Calculator:
   3.  Select I_Line, and choose to Copy the plot to top of stack of calculator.
   4.  Choose Sample, and define the following parameters:
       •  Sample in: Time
       •  Specify by: Size
       •  Start = 0.0485
       •  Stop = 0.058
       •  Size = 500
   5.  Choose OK to accept the values and return to the Signal Calculator.
   6.  Choose the integrate button to integrate the results.
   7.  Enter 0.0095 in the Name/Constant field.
   8.  Choose / to divide the results and obtain the average or mean values.
   9.  Choose Preview. The last number in this plot is the average value.
    10. Choose max. If the last number is the maximum value, this command displays that value, with
       the top value as the x-component and the bottom as the y-component.

This calculation returns a value of 3.18 amps. RMxprt calculates a value of 3.22 amps.


Copper Loss

                                                                  2
Use PlotData to calculate the copper loss, which will be the I  R losses. Do this by calculating the RMS
phase current.

➤   From the Signal Calculator, compute the copper loss:
    1. Select I_A, and choose Copy to copy the A-phase current to the top of the stack.
    2. Choose Sample, and define the following parameters:
       •   Sample in: Time
       •   Specify by: Size
       •   Start = 0.0388
       •   Stop = 0.0578
       •   Size = 500
    3. Choose OK to accept the values and return to the Signal Calculator.
    4. Choose Push to duplicate the entry.
                                                                                       2
    5. Choose * to multiply the value in the top of the stack by itself, to obtain I  .
    6. Choose the integrate button.
    7. Enter 0.019 in the Name/Constant field.
    8. Choose / to calculate the average.
    9. Choose the square root button to take the square root of the quantity.
    10. Choose Preview. The last number in this plot is the RMS value.
    11. Choose max. If the last number is the maximum value, this command displays that value, with
       the top value as the x-component and the bottom as the y-component.

This calculation returns a value of 2.4 amps RMS. The value given by RMxprt is 2.66 amps RMS.

The total copper loss, including both A and B phase, is:
                                                              2
                          Copper Loss = (2.4 amps)  * 4.49 ohms * 2 phases

                          Copper Loss = 51.7 watts

RMxprt calculates a value of 63.9 watts.

Average Input Power

This is the input voltage multiplied by the input current. From the calculation above, the average input
current is 3.18 amps. Thus, the input power is:

              Pinput = 220 watts * 3.18 amps

              P        = 700 watts
                input

The value given by RMxprt is 708 watts.

Efficiency

The efficiency is the ratio of the output power to the input power.

                          Efficiency = 601.5/700 * 100%

                          Efficiency = 86 %

The value calculated by RMxprt is 85%.

Now that you have computed a number of motor parameters, compare field quantities between RMxprt
and EMpulse.

Choose File/Exit to exit the plot data window.


上面的计算是V11.1以下版本的,V12以上版本关于平均转矩、平均负荷电流等参数的计算由于软件升级反而不知怎么算了

V12后处理器没有了2D PLOT接口,请高手演示一下在V12里怎么利用转矩、电流等曲线计算平均转矩、平均电流。

kt266a

顺便问一下：ansoft是怎么画曲线的？比如画某个体的“损耗——时间”曲线。

或者对一些柱坐标系下半径相同的点画“磁密——电角度”曲线。

kt266a

我的理解是：  ohmic  loss 是根据每个节点的电密和电导率计算的，是直流、涡流损耗的总和

total loss  好像是时间平均值。ansoft没给出更详细的定义和公式。我不敢多说。

更具体的损耗，比如涡流损耗什么的，应该是自己用场计算器写公式计算吧？

kt266a

total  loss难道是瞬态求解设置中开始到结束所有时刻的积分平均值？

大家都知道瞬态算出的损耗在最初的一个周期是不准确的。

ansoft为什么不让大家自己设置时间范围？

kt266a

不知道怎么回事，我计算一台大型同步发电机的端部损耗特别大。这个很难说的通。

kt266a

最荒唐的是：同样的模型，同样的剖分，同样的激励，同样的时刻和部件……12算出的ohmic loss是203W，13算出的是34496W

磁场云图倒是没发现什么特别不对劲的地方

龍が如く

铁耗这东西 目前据我所知 学术界还没有个完美的数学模型可以准确计算的 所以楼主想通过有限元软件准确计算出来 基本不可能 计算结果只能是个参考

kt266a

能有个说的过去的参考值也好啊。像这样动不动差上几百倍，实在是受不了啊。

kt266a

我在场计算器选择时刻以后再输入下面的内容，求dzyb这个体的涡流损耗。大家看看有没有错误：
Scl : Integrate(Volume(dzyb), Ohmic-Loss)

kt266a

我正在做瞬态场涡流损耗的对比测试
三维模型是http://bbs.simol.cn/thread-668-1-3.html里面的。在此感谢jixnjie 前辈！



软件环境：
ansoft11.1      2003
ansoft12.2      2003
ansoft13         xp64

kt266a

ansoft13已经算完，对于core部件的ohmic  loss ：0s ，7.16083e-8 w；0.03s ，0.00148 w

kt266a

ansoft12.2已经算完，对于core部件的ohmic  loss ：0s ，6.42678595524299E-018 w；0.03s ，0.000317735848634786 w

kt266a

ansoft11.1已经算完，对于core部件的ohmic  loss ：0s ，9.40729 E-018 w；0.03s ，0.289084 w

kt266a

大家不妨也算一下。我已经弄不明白哪个版本还算可信了。

sczclever

realy puzzle!

hanzg

到底哪个准，只有与实物比较测试了

guoren312

我来看看，感受一下气氛