DiSiNTiGR8

I must correct myself. After updating to version 3384, a new option appeared.
Settings -> Battery -> Page 2 -> Low Noise mode

Enabling this setting shuts the inverter down, "Grid Mode changed" appears on the screen and after roughly 1 minute it turned on again. Now the frequency is moved from audible 15 kHz to barely audible 20 kHz. This is a very huge improvement.
 

When I was trying to figure out the buzzing on my setup I isolated the inverter everywhere except on its grid input. I also switched the house over to Eskom again. So the inverter was basically just another consumer from the grid like other appliances. It still sent the 15000Hz through appliances in this case. 

I have asked them for details on how to raise a ticket for Deye owners to get their issues resolved. Will let you know. 

I was just about to post, the mail trail I have had going with the Deye / Sunsynk engineer brought a fix this afternoon.
They pushed firmware update 3.3.8.4, inverter rebooted (power went out on essentials) then they pushed a setting that made F13 Grid mode changed Fault (essentials went out again) then when the inverter powered back up the noise was gone. Can also see the 15000Hz moved to 20000Hz now. I am so happy the house is quiet now. So don't get a fright when they do this process on your inverters when the Fault comes in, I got a shock and thought something broke on the new firmware. 

I was just about to post, the mail trail I have had going with the Deye / Sunsynk engineer brought a fix this afternoon.
They pushed firmware update 3.3.8.4, inverter rebooted (power went out on essentials) then they pushed a setting that made F13 Grid mode changed Fault (essentials went out again) then when the inverter powered back up the noise was gone. Can also see the 15000Hz moved to 20000Hz now. I am so happy the house is quiet now. So don't get a fright when they do this process on your inverters when the Fault comes in, I got a shock and thought something broke on the new firmware. 

That's great news! A lot easier than to make a filter!

I was just about to post, the mail trail I have had going with the Deye / Sunsynk engineer brought a fix this afternoon.
They pushed firmware update 3.3.8.4, inverter rebooted (power went out on essentials) then they pushed a setting that made F13 Grid mode changed Fault (essentials went out again) then when the inverter powered back up the noise was gone. Can also see the 15000Hz moved to 20000Hz now. I am so happy the house is quiet now. So don't get a fright when they do this process on your inverters when the Fault comes in, I got a shock and thought something broke on the new firmware. 

Hi all
Here is the update on how to make your own inductor to filter out the noise coming from the inverter.
First off, you will need a core to wind your wire around. A toroidal core will be the easiest to work with and will also radiate the least amount of EMI. The bigger the core, generally speaking, the better as you will be able to get more windings on it with a thicker wire. Here is the biggest one I could find with a good permeability:
https://www.mantech.co.za/ProductInfo.aspx?Item=82M1485
 
The enamel wire diameter will determine the amount of amps it will be able to handle. I would recommend using 1-1.6mm diameter wire. You can find a good variety from Communica.
https://www.communica.co.za/products/eccw-1-25
Just note that thicker wires will be more difficult to work with, but will obviously be able to handle more current. Here is a website to give you an idea of the current carrying capability of different wire thicknesses:
https://www.powerstream.com/Wire_Size.htm
 
How many turns do you need? Well you would want to wind the inductor to get you an inductance of at least 1mH, but more than 5mH would probably be overkill. You can calculate the exact number of windings you'll need with a nifty program called Coil64:
https://coil32.net/download-coil64-for-windows.html
For the above-mentioned core and wire, you will need about 50turns to get 1mH and 75turns for 2mH. (The inductance goes up with the square of the number of windings and the resistance of the wire goes up linearly with number of windings).
 
As mentioned before, you would place this filter "In-Line" by breaking either live or neutral and join the break through the inductor. 
Also, be sure to use a surge protector on the load side of the filter as inductors might cause voltage spikes when the current draw through it changes.
 
I still need to test my toroidal filter to see how many amps it can handle, but for now I can definitely say that it works in filtering out the noise to a level that is completely inaudible. The previous filter I made with the E-core handles 8 amps without getting too hot. I would guess that the smaller toroidal core will do about 3 amps, as I had to use a thinner 1.25mm wire instead of the 2mm wire.
Hope it helps!
 

Hi @DiSiNTiGR8
 
Most of these off-the-shelf filters are not very likely to work unfortunately. I have wasted a couple of bucks to try these out too. Almost all of them are designed to filter out frequencies in the CRISPR defined conducted emissions band, which starts from about 150kHz and ends at 30MHz.
Some do seem to have good filtering properties at 15kHz on their datasheets, but one should be careful for the "50Ω/50Ω symmetrical" condition the tests were run at. This condition refers to the characteristic impedance (transmission line theory) of the test system and is usually only applicable to RF circuits and not mains power. The test condition for an inverter would be closer to something like 0.1Ω/100Ω. Under this test condition most of these filters perform very poorly or can even cause resonances making the problem worse as in you case.
If you are looking for an off-the-shelf solution, you should get a filter with an inductance in the 1-5mH region (the higher the better but past 5mH it would be overkill). Just be careful, some datasheets also list the Common-Mode inductance, which wont be helpful in our case. A differential inductance (aka a normal series inductor as everyone knows it) is needed.
I am yet to find an off-the-shelf solution that has a large enough inductance and current rating. Usually you get to pick either or, but not both.
Regarding a DIY solution, I am looking for a supplier of a large toroidal core, which will make the whole winding process very easy. This will make it a viable solution for the general hobbyist. Will make a post as soon as I find something.
 
Cheers for now
Wiggly

Still an issue on mine, I had them update my firmware two weeks ago, no change. Best would be to try visit someone with a Sunsynk installation and see if you can or cannot hear the noise. 

I had a Growatt 5KW temporarily in my house during the time my Sunsynk inverter was at Sunsynk JHB for them to look at this noise issue. I could not hear any noise from my devices with the Growatt inverter.
Using the Phone app to show sound frequency I could see the Growatt spike at just under 20000Hz, a frequency no one can hear at all, even right at the inverter.
Some people also can't hear the 15000Hz noise my Sunsynk is emitting throughout the house. Unfortunately I can.
So in my view the problem is the switching frequency that Sunsynk uses (on the 5kw inverters at least) is too low so some people can hear it and that this frequency noise makes it out of the inverter into the house wiring and devices.

I had a Growatt 5KW temporarily in my house during the time my Sunsynk inverter was at Sunsynk JHB for them to look at this noise issue. I could not hear any noise from my devices with the Growatt inverter.
Using the Phone app to show sound frequency I could see the Growatt spike at just under 20000Hz, a frequency no one can hear at all, even right at the inverter.
Some people also can't hear the 15000Hz noise my Sunsynk is emitting throughout the house. Unfortunately I can.
So in my view the problem is the switching frequency that Sunsynk uses (on the 5kw inverters at least) is too low so some people can hear it and that this frequency noise makes it out of the inverter into the house wiring and devices.

Sold to member Abe53, thanks for the smooth sale. 

I have found that devices with the Power brick type PSU like a laptop or a screen with external power supply don't produce the noise.
My PC and high refresh rate Dell screen (built in PSU) make the noise the loudest and are really the only things I would not be able to get used to. The Neon tube lights in the Garage also emit the noise very loud. I can just replace those with LED so that would be fine. 
The rest of the house is quiet enough that I only hear it when walking past the TV's or the original DB board of the house which is weird as its only breakers in there and earth leakage, yet they also emit the noise.  
 
I am really hoping that they can change this 15000Hz frequency in the inverter firmware to something higher which would remove the issue for everyone that is able to hear it. Hopefully the components can switch at a different frequency and they can do it. 
 

Hi Members. 
To update on my above post, I ended up booking my inverter in to Sunsynk in JHB on 16 August 2022.
I received a call on 19 September that they had looked at the inverter and would like to know which noise I am complaining about. Explained the whole situation to them and was told the inverter is not faulty and that I have super sensitive hearing.
I have received a managers email address which I escalated the matter to further. Waiting on further response now from him. 
 
Due to frequent load shedding and the long wait time  I bought a Growatt 5kw inverter as a stop gap. This emits no noise from my devices in the house at all but lacks the additional features the Sunsynk has that I would like to make use of again.
These images show the Sunsynk noise at 15000Hz from my computer screen vs the Growatt which shows no noise. 
 
 

Hi Members. 
To update on my above post, I ended up booking my inverter in to Sunsynk in JHB on 16 August 2022.
I received a call on 19 September that they had looked at the inverter and would like to know which noise I am complaining about. Explained the whole situation to them and was told the inverter is not faulty and that I have super sensitive hearing.
I have received a managers email address which I escalated the matter to further. Waiting on further response now from him. 
 
Due to frequent load shedding and the long wait time  I bought a Growatt 5kw inverter as a stop gap. This emits no noise from my devices in the house at all but lacks the additional features the Sunsynk has that I would like to make use of again.
These images show the Sunsynk noise at 15000Hz from my computer screen vs the Growatt which shows no noise. 
 
 

Hi Members. 
To update on my above post, I ended up booking my inverter in to Sunsynk in JHB on 16 August 2022.
I received a call on 19 September that they had looked at the inverter and would like to know which noise I am complaining about. Explained the whole situation to them and was told the inverter is not faulty and that I have super sensitive hearing.
I have received a managers email address which I escalated the matter to further. Waiting on further response now from him. 
 
Due to frequent load shedding and the long wait time  I bought a Growatt 5kw inverter as a stop gap. This emits no noise from my devices in the house at all but lacks the additional features the Sunsynk has that I would like to make use of again.
These images show the Sunsynk noise at 15000Hz from my computer screen vs the Growatt which shows no noise. 
 
 

Hi Members. 
To update on my above post, I ended up booking my inverter in to Sunsynk in JHB on 16 August 2022.
I received a call on 19 September that they had looked at the inverter and would like to know which noise I am complaining about. Explained the whole situation to them and was told the inverter is not faulty and that I have super sensitive hearing.
I have received a managers email address which I escalated the matter to further. Waiting on further response now from him. 
 
Due to frequent load shedding and the long wait time  I bought a Growatt 5kw inverter as a stop gap. This emits no noise from my devices in the house at all but lacks the additional features the Sunsynk has that I would like to make use of again.
These images show the Sunsynk noise at 15000Hz from my computer screen vs the Growatt which shows no noise. 
 
 

Hi Members. 
To update on my above post, I ended up booking my inverter in to Sunsynk in JHB on 16 August 2022.
I received a call on 19 September that they had looked at the inverter and would like to know which noise I am complaining about. Explained the whole situation to them and was told the inverter is not faulty and that I have super sensitive hearing.
I have received a managers email address which I escalated the matter to further. Waiting on further response now from him. 
 
Due to frequent load shedding and the long wait time  I bought a Growatt 5kw inverter as a stop gap. This emits no noise from my devices in the house at all but lacks the additional features the Sunsynk has that I would like to make use of again.
These images show the Sunsynk noise at 15000Hz from my computer screen vs the Growatt which shows no noise. 
 
 

@Derek Ramos Take a look at this as well...
It may be the inverters fault... high frequency noise+harmonics could be preventing the communications of the meter interface... I think someone from Sunsynk needs to come to the party and shed light on this issue, supposedly the Inverters were approved with a switching frequency of 19kHz and supposedly now they are running at 15kHz, which to some of us, who didn't squander our time with loud rock'n'roll are annoyed by this 15kHz noise.... at 19kHz, very few would hear it, but 15kHz... problem... why would we use 20Hz to 20kHz as the measure for speaker sound reproduction and then run a "noise source" at 15kHz... heck it should run at 21kHz just for good measure and peace of mind and this may then also shift the interference signal superimposed on the 50Hz AC power enough so it won't interfere with these prepaid meters either... maybe... @Sunsynk Limited @Sunsynk inverters ?? any feedback or information to be shared? and how about a list of all the firmware versions past and present with information about what they "fixed" or changed and when was this switching frequency change put into effect? from which firmware version?