Adding a high frequency signal to the powerline

Thread Starter

Ron Joel

Joined Jun 30, 2017
3
Hello. First of all - no electrical engineer writing here, so bear with me please.
I have an asignement to design a high frequency signal generator that is going to be added to the powerline and added to the power signal ( 3-phase, 230V, 50 Hz)
The high frequency signal parameters are 150 kHz 20V peak to peak. Basicaly no idea how the generator could look. Any help would be appreciated!

Thank you.
 

dl324

Joined Mar 30, 2015
13,554
Welcome to AAC!

Is this signal to be used locally; i.e. within the same building?

Try reading this Wikipedia article on the X10 protocol.
 

Papabravo

Joined Feb 24, 2006
17,312
A couple of points:
  1. Power lines make really terrible transmission lines for anything but power frequencies.
  2. The nature of the transformers used in power distribution makes signal transmission difficult
  3. 150 kHz is not considered high frequency
That said there have been attempts to use power lines for data transmission which were less than successful. One basic argument was related to the interference that it caused to licensed users of the spectrum. The power lines are not shielded and they radiate prodigious amounts of energy.

Here is a link to the Wiki, which contains some useful links.
https://en.wikipedia.org/wiki/Broadband_over_power_lines
 
Last edited:

Thread Starter

Ron Joel

Joined Jun 30, 2017
3
Welcome to AAC!

Is this signal to be used locally; i.e. within the same building?

Try reading this Wikipedia article on the X10 protocol.
Thank you!
No, not locally. The signal would be for monitoring of non-technical loses in the powerlines (energy tampering).
 

ian field

Joined Oct 27, 2012
6,539
Hello. First of all - no electrical engineer writing here, so bear with me please.
I have an asignement to design a high frequency signal generator that is going to be added to the powerline and added to the power signal ( 3-phase, 230V, 50 Hz)
The high frequency signal parameters are 150 kHz 20V peak to peak. Basicaly no idea how the generator could look. Any help would be appreciated!

Thank you.
historically - there's been hundreds of powerline protocols - but the radio hams are getting pretty cheesed off about the QRM.
 

tcmtech

Joined Nov 4, 2013
2,867
The simplest way is with a basic capacitive coupling between the transmitter output and whatever line you want to feed the single into.

Say for instance if you used a .1 uF capacitor.

At 60 Hz it would have a capacitive impedance of ~27,000 ohms but at 150 KHz it would only be about 10.6 ohms thus allowing the higher frequency single to easily super impose itself on the AC line without letting much of that AC line signal feedback to the transmitter output. Which if needed a inductor between transmitter output and its ground line could be used to work in reverse allowing the low frequency power line signal to be effectively pulled down to near nothing while still providing no relevant load to the higher frequency output.
 

Thread Starter

Ron Joel

Joined Jun 30, 2017
3
The simplest way is with a basic capacitive coupling between the transmitter output and whatever line you want to feed the single into.

Say for instance if you used a .1 uF capacitor.

At 60 Hz it would have a capacitive impedance of ~27,000 ohms but at 150 KHz it would only be about 10.6 ohms thus allowing the higher frequency single to easily super impose itself on the AC line without letting much of that AC line signal feedback to the transmitter output. Which if needed a inductor between transmitter output and its ground line could be used to work in reverse allowing the low frequency power line signal to be effectively pulled down to near nothing while still providing no relevant load to the higher frequency output.
That was a great answer kind sir! Can you please explain what kind of transmitter could be used?
 

tcmtech

Joined Nov 4, 2013
2,867
That was a great answer kind sir! Can you please explain what kind of transmitter could be used?
Well if you don't know what sort of transmitter you are using for your own project you are already in way over your head on this idea and general concept.
 
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