EMI Filter 230Vac Source Inductance

Thread Starter

SheldonNyce

Joined Aug 6, 2019
26
I'm busy designing an AC line filter. Trying to size the pi capacitor, but I CANNOT find a good estimate for AC wall plug (230V) source inductance ANYWHERE.

I would imagine that it is extremely dependent on the utility supply cabling, but are there not at least some sort of range values available? Like, 50uH < Ls < 50mH?

Would really appreciate any thoughts on the matter
 

Marc Sugrue

Joined Jan 19, 2018
64
EMI is typically done via Line Impedance Stabelisation Network (LISN) whose specification should be defined by the requirements you are testing to. If your designing a filter i would have thought your focus should be the load impedance you intend on driving.
 

Thread Starter

SheldonNyce

Joined Aug 6, 2019
26
Indeed, but in order to define the parameters in which to select and define the pi capacitor value to counteract the effect of the source inductance - I need to know what the source inductance is.

I cannot measure the source inductance, and there are no source inductance values available on the web. That's why I am hoping someone might know of a range in which to operate and design for.
 

Marc Sugrue

Joined Jan 19, 2018
64
Hi SheldonNyce,
Indeed, but in order to define the parameters in which to select and define the pi capacitor value to counteract the effect of the source inductance - I need to know what the source inductance is.

I cannot measure the source inductance, and there are no source inductance values available on the web. That's why I am hoping someone might know of a range in which to operate and design for.
If you look at your requirements the type of LISN shold be defined against the standard you have to comply too. Depending on your LISN your inductance will be different.

https://en.wikipedia.org/wiki/Line_Impedance_Stabilization_Network

"The anticipated inductance of the power line for the intended installation of the EUT also plays a role in identifying the correct type of LISN needed for testing. For example, a connection in a building will often use 50 μH inductor, whereas in automobile measurement standards a 5 μH inductor is used to emulate a shorter typical wire length.[4]"
 
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