That strongly suggests DC or low frequency modelling.newengr said:
The values for a range of frequencies are always available - use Google. One shouldn't keep within the limitations of any simulation and rely on it whatever; there is a lot of real world information about these things. Simulations have a habit of making assumptions about what you want. This allows you to get an 'answer' out but it should always be scrutinised but there are pitfalls that you have to accept when you want too much 'help' in driving the software. (GIGO)tech99 said:
It is for use in DC so it seems the static value is suitable. There will be some high frequency content since there is switching in the converter, but DC is dominant.Baluncore said:
In your thread title and first post you used the words "optical vs. static", but now you changed to "DC or electrostatic". DC is analogous to static, but optical and electrostatic are completely different. Can you say more about what you are simulating?newengr said:
This kind of implies that you are simulating capacitors in switched mode power supplies (SMPS, using SPICE?)? If so, you need to take into account the equivalent series resistance (ESR) of the capacitors, since that is a major part of what causes ripple voltage in the output of SMPS.newengr said:
Sorry for jumping all over the place. I want to design a FEA simulation for a capacitor considering different dielectrics and other things like dielectric thickness and other geometries. I found static and optical dielectric constants which is what prompted this post. I wasn't sure what the difference was or when to use which. You mentioned DC or low frequency modeling so I just wanted to confirm that I am interested in DC. I just mentioned the high frequency switching content in case that added something else to the discussion. Looking back, I don't think it did. I'm not doing converter or component modeling considering electrical performance, but I'm more so considering material properties dependent and the physical geometry. So I think FEA is appropriate here.berkeman said:
What other parameters are available for dieletrics in that simulation environment? How can you model ESR, for example? And loss tangent?newengr said:
Through DC simulation I'm able to model the conductivity, permittivity, and permeability of the plates as well as the dielectric. ESR should be able to be modeled through conductivity. Loss tangent is a function of capacitive current and resistive current so I suppose you could determine the loss tangent from simulation. If I wanted add loss tangent as a parameter, I would I have to use the RF module which I'm not using here. I'm mainly considering parameters that effect e-field intensity.berkeman said:
The optical dielectric constant is a measure of the material's response to an electric field at high frequencies, while the static dielectric constant is a measure of the material's response to an electric field at low frequencies.
It depends on the frequency range of the simulation. If the simulation involves high-frequency electromagnetic waves, then the optical dielectric constant is more important. However, for low-frequency simulations, the static dielectric constant is more relevant.
The optical dielectric constant affects the propagation of high-frequency waves, while the static dielectric constant affects the behavior of low-frequency waves. Therefore, the choice of dielectric constant can significantly impact the accuracy of the simulation results.
Yes, in some cases, the optical and static dielectric constants can be equal for a material. This usually happens for materials with a relatively narrow range of frequencies in which their dielectric response is constant.
The optical dielectric constant is typically measured using techniques such as ellipsometry or spectroscopic reflectometry, while the static dielectric constant is measured using methods like capacitance measurements or dielectric spectroscopy.
