"Audio frequency" in electrical engineering

[Antonio Perez Martinez]

I've been asked for some quality grid parameters required to design an electrical facility, like harmonics, voltage and frecuency tolerances. One of the parameters is "Audio frequency" to be considered. I had never heard of this. I suppose it is something to characterize the ripple of the voltage wave but I'm not able to find any information. Does anyone know?

Thanks for your help.

 

[LionelHutz]

Maybe it's referring to audible noise, such as transformer hum.

 

[waross]

My information is decades old and definitions may have changed but I remember "Audio Frequencies" to be in the range of 20Hz to 20,000Hz.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[AntonioPerez]

Thanks for your comments. I think I discovered what it is. It seems to be some kind of system for data transmission by means of overlayed audio frequency signal to voltage wave from power grid to power plants. It is used, for example, to switch between day and night power-tariffs.

https://www.epro.at/en/products/feed-in-transformers/audio-frequency-feed-in-transformers

 

[FacEngrPE]

That system is also used for protection coordination on the bulk power system. The signals are usually contained to the bulk power system by line traps.

https://en.wikipedia.org/wiki/Power-line_communication[/URL]]Power-line communication (PLC) is the carrying of data on a conductor that is also used simultaneously for AC electric power transmission or electric power distribution to consumers.

The variant of this system used for smart metering signaling operates at a High frequency that is unlikely to cause audio interference.
If you encounter a problem with audio frequency interference in your power line, a 60 Hz (50 Hz?) low pass filter in the power supply (or power feeder) should provide a solution.

https://www.mouser.com/c/power/power-condition/?operating frequency=60 Hz

 

[cranky108]

Sounds like the old Power line carrier we used years ago. Except there we used radio frequencies.

 

[bacon4life]

One other way the term "audio frequency" might be used is in reference to interference with frequencies used by telephone systems. Certain kinds of power grid equipment configurations can produce electrical noise that distorts the audio signal on telephone wires.

 

[crshears]

My former utility had for many years System Voice Channels that employed an audio range of Power Line Carrier for communication with certain far-flung stations; in the main it worked fairly well.

Utilities may use audio frequencies on power distribution systems to switch off groups of water heaters for peak shaving purposes; most homeowners never notice.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]