拉普拉斯元件实现声阻运算（pspice) - 基础理论室 - 声学楼论坛

Modeling a frequency dependent inductor for AC sweep analysis

PROBLEM:
How do I model a frequency dependent inductor for AC sweep analysis?

SOLUTION:
The impedance of an inductor is:

Z = L * s

where

s = j * 2 * PI * Frequency

In a frequency dependent inductor, the "L" in the above formula changes with frequency.

If you know L as a math function of frequency, then:

Use a GLAPLACE device.
Connect the positive and negative inputs to the positive and negative outputs, respectively.
Write the transform expression as 1/(<L>*s), where <L> is replaced by the desired math formula, with frequency replaced by abs(s)/6.283185.

For example, if L = 1 / sqrt(Frequency), then write the transform expression as:

1/(1 / sqrt(abs(s)/6.283185)*s) or sqrt(abs(s)/6.283185)/s

http://www.orcad.com/documents/community.faqs/pspice/020020.aspx

更详细的介绍查阅实例(要翻越和谐之墙): Google搜索"Modeling a frequency dependent inductor for AC sweep analysis"的第二个结果:

http://acousticians.blogspot.com/2012/10/modeling-frequency-dependent-inductor.html

[此贴子已经被作者于2013-05-07 20:03:13编辑过]

以下是引用liheng_rd在2013-05-08 00:30:01的发言：

举个实例吧：

单孔的声阻：R=sqrt(2ηρw)*(l/a+2)/(π*a^2)

假设:η=1/2;ρ=1/2;l=1；a=1;

则计算的R=[sqrt(π*frequency)*3]/π

那么XFORM的参数是1/(([sqrt(π*abs(s)/6.28)*3]/π)*s)这个表达式吗？

要把分母最后的s去掉, 即XFORM= 1/Z =1/R= 1/([sqrt(pi*abs(s)/6.28)*3]/pi)

假设单孔的声质量表达式子L=sqrt(π*frequency)*3]/π ,

那么XFORM的参数才是XFORM= 1/Z =1/(L*s)=1/(([sqrt(π*abs(s)/6.28)*3]/π)*s)

1/Z中的Z表示阻抗

以下是引用lhyjs_63在2013-06-28 15:33:50的发言：
小马哥，nisa您们好：

第3点中，3) 考虑到拉普拉斯变量s = jω = j·2πf, 故将上述转换函数中的频率改写成f = abs(s)/6.28

有不明白请指教，s = jω = j·2πf，那么 f = s / j·2π, 又因为 j = √-1 所以 f = s / (√-1 ·2π) = -s·√-1 / 2π, 如何得到 f = abs(s)/6.28 的呢，谢谢。

你想多了; abs（）是求模值，即abs(s)=abs(jω)=ω, ω=2πf → f=ω/2π;

二、三楼的内容说得够详细了啊；自己多动脑子思考才好理解透。

主题：拉普拉斯元件实现声阻运算（pspice)