What's interesting about this machine is that there is a Single Neutral Bar for both input & output. 

10 hours ago, BritishRacingGreen said:

Yes , if you want to entertain unbalanced loads , you need a hard neutral. If your DC side is single ended , then your AC side can only be delta , so you need the magnetics to convert to Y .

If you have a split DC supply , where the midpoint then become neutral , then your three half bridges produce effectively Y configuration without further need of conversion. But at 100 kW it's probably as costly and difficult to entertain the extra magnetics to convert the single battery/pv supply to split supply.

That must be an awfully amount of copper needed  though for that delta to Y conversion, because it's low frequency as well .

One advantage of course is the load is decoupled from any DC.

 

By the way this not to confirm what the function of that transformer is of the ATESS , it could very well be something else.  I am just in agreement to @TaliaB observation and logic.

10 hours ago, Steve87 said:

What's interesting about this machine is that there is a Single Neutral Bar for both input & output. 

Which is weird , because when the incoming neutral is lost , say via a double breaker being tripped , then the output neutral will be floating when ATESS is in battery mode.

I've searched everywhere I don't see any other neutral. 

5 hours ago, BritishRacingGreen said:

Which is weird , because when the incoming neutral is lost , say via a double breaker being tripped , then the output neutral will be floating when ATESS is in battery mode.

Checked the manual again it clearly says AC output & Grid Neutral. So it must float otherwise this would cause all sorts of havoc. 

4 minutes ago, Steve87 said:

Checked the manual again it clearly says AC output & Grid Neutral. So it must float otherwise this would cause all sorts of havoc. 

Yep @Steve87 you are correct it is on page 6 of the manual one neutral for load and grid marked number 12 on the picture.

@BritishRacingGreen @Steve87  I  copied this explanation from the Atess site how a single neutral is achieved.

"

A Δ/Y-shaped transformer is added between the 3-leg inverter and the load. The secondary Δ/ Y-shaped connection can create current path for the neutral current generated by unbalanced load, while the primary connection provides circulating current path for the zero-sequence current caused by unbalanced load or triplen subharmonics.

 

We use this topology to combine with the ATESS control logic: during grid connection, the software will control the inverter to perform phase lock referencing to grid frequency and voltage, and output synchronously; when off-grid, ATESS inverter can precisely control the output voltage and frequency, so as to ensure that the voltage of each phase is consistent within the allowable tolerance. With all this, ATESS energy storage inverter turns out to be able to handle 100% unbalanced three-phase load, which means that a 150kw three-phase inverter can run with single-phase load of 50KW in any phase, providing an ideal solution for load variability. (If there are respectively more inductive loads, it needs to be recalculated according to the actual load operation

6 minutes ago, TaliaB said:

@BritishRacingGreen @Steve87  I  copied this explanation from the Atess site how a single neutral is achieved.

"

A Δ/Y-shaped transformer is added between the 3-leg inverter and the load. The secondary Δ/ Y-shaped connection can create current path for the neutral current generated by unbalanced load, while the primary connection provides circulating current path for the zero-sequence current caused by unbalanced load or triplen subharmonics.

 

We use this topology to combine with the ATESS control logic: during grid connection, the software will control the inverter to perform phase lock referencing to grid frequency and voltage, and output synchronously; when off-grid, ATESS inverter can precisely control the output voltage and frequency, so as to ensure that the voltage of each phase is consistent within the allowable tolerance. With all this, ATESS energy storage inverter turns out to be able to handle 100% unbalanced three-phase load, which means that a 150kw three-phase inverter can run with single-phase load of 50KW in any phase, providing an ideal solution for load variability. (If there are respectively more inductive loads, it needs to be recalculated according to the actual load operation

You were right, 50kw single phase operation per phase is way cool .

This ATESS machine internal layout and wiring  reminds me of old legacy railway inverters  ,only 15kW  and three quarters the size of the ATESS.  This in the late 70s , no microprocessor , control was discrete analogue, bits and pieces of TTL digital logic.

The DC-AC converter was an SCR bridge , I never heard of MOSFETS then. The SCRs were very robust but it wouldn't turn off ,for that there was a complicated and bulky commutation circuit to turn them off .

One day I witnessed standing in front of an inverter with the inverters door half way open . The commutation failed , the SCR latched , and huge DC currents flew thru the magnetics .The transformer became a monster magnet , attracted the door and banged it closed. The one technician that was with me ran out of the relay room , not to come back and waited outside until we left the site.

You can see there how slow some circuit breakers can be. It took a couple of seconds to break. Those machines were robust, mostly those SCR could take that beating. They were very big , stud mounted.

12 minutes ago, BritishRacingGreen said:

This ATESS machine internal layout and wiring  reminds me of old legacy railway inverters  ,only 15kW  and three quarters the size of the ATESS.  This in the late 70s , no microprocessor , control was discrete analogue, bits and pieces of TTL digital logic.

The DC-AC converter was an SCR bridge , I never heard of MOSFETS then. The SCRs were very robust but it wouldn't turn off ,for that there was a complicated and bulky commutation circuit to turn them off .

One day I witnessed standing in front of an inverter with the inverters door half way open . The commutation failed , the SCR latched , and huge DC currents flew thru the magnetics .The transformer became a monster magnet , attracted the door and banged it closed. The one technician that was with me ran out of the relay room , not to come back and waited outside until we left the site.

You can see there how slow some circuit breakers can be. It took a couple of seconds to break. Those machines were robust, mostly those SCR could take that beating. They were very big , stud mounted.

Small world.I did my trade at the railways in 1975 as n sparkie and i can relate to what you are saying. 2 years after qualifying i started to work for EC Lennings where i was involved building dc controllers for the mining industry. Early models of these dc speed controllers for underground locomotives where camtactors basically cutting out big resistors to change speed. We then built thyristor speed controllers to replace the camtactors. The huge thyristors mounted on solid aluminum blocks 6 to 8 in parralel. The locomotives used 96 cell lead acid traction batteries, current limit set at 2300 amps. The line breaker contactor(safety)used had blow out magnets fitted to handle arc across the contacts. These locomotives where loaded with ore and transported to the skip for removal to the surface. So yes you need to be respectful working with dc of that magnitude.

More progress on this Project...a very interesting PV DC combiner box that has most ppl scratching their heads. It's a 5 in & 1 out. De rated to 125A. Will need a larger DC MCB if more PV is added. However, this plant will not grow that large. All our AC Protection is in place now it's just to terminate into the Inverter & run the Earth. Our hold up has been the FreedomWon HV 40/32 Lithium Batteries. Looks like FreedomWon can't get them out quickly enough. Some delays on the 15/12 LV units also. 

Here is the ATESS ATS. We will pair this entire lot up once we get the FreedomWon HV batteries. 

@Steve87Just as n matter of interest does the ATESS have arc fault detection on the solar system when you have faulty connections on the solar panels causing noise. I know the Sunsynk can detect arc fault error F63. Seeing that the ATESS is high voltage dc.

Hi @TaliaBi cannot talk very intelligently on the ATESS wrt to your question. A week ago this machine was just a heavy box. This last week it proved itself to be very robust and heavy duty. Sucking up large 3 phase loads for fun. Id expect nothing less with the huge transformer inside. This poor client has forced this system off grid and the baptism by fire has been crazy. No ESKOM supply the last 2 days. I know a lot more about her now and the ATESS team has created a very very industrial antique toaster here. She is heavy duty.

The Growatt brigade will feel proud. She is OEM Growatt. My first experience on any Growatt but i cant really call her fully Growatt as i have no experience thereof. 

The Pros: 

Remote setting and monitoring through the Enerlog module. It costs a lot tho, R15k worth. But you can even turn the machine on remotely etc. Massive Transformer makes pulling a 8kW 3 phase pump look like childs play. This farm has at least 4 of these and the ATESS didnt even blink. Industrial quality that is modular and repairable if required. 

The Cons:

You need specialist help to commission. The instructions are poor at best and you need someone who has tamed her prior. Based on a first experience, the labelling is not logical and you constantly scratching your head. This first time was a voyage of discovery. The next time will be much easier as with much in life. 

 

34 minutes ago, Steve87 said:

Hi @TaliaBi cannot talk very intelligently on the ATESS wrt to your question. A week ago this machine was just a heavy box. This last week it proved itself to be very robust and heavy duty. Sucking up large 3 phase loads for fun. Id expect nothing less with the huge transformer inside. This poor client has forced this system off grid and the baptism by fire has been crazy. No ESKOM supply the last 2 days. I know a lot more about her now and the ATESS team has created a very very industrial antique toaster here. She is heavy duty.

The Growatt brigade will feel proud. She is OEM Growatt. My first experience on any Growatt but i cant really call her fully Growatt as i have no experience thereof. 

The Pros: 

Remote setting and monitoring through the Enerlog module. It costs a lot tho, R15k worth. But you can even turn the machine on remotely etc. Massive Transformer makes pulling a 8kW 3 phase pump look like childs play. This farm has at least 4 of these and the ATESS didnt even blink. Industrial quality that is modular and repairable if required. 

The Cons:

You need specialist help to commission. The instructions are poor at best and you need someone who has tamed her prior. Based on a first experience, the labelling is not logical and you constantly scratching your head. This first time was a voyage of discovery. The next time will be much easier as with much in life. 

 

Well done Steve you are most probably one of the first installers in SA taming this beast with obvious hazardous working enviroment for your team due to HV DC.

Edited June 12, 20233 yr by TaliaB

So all in all this ATESS with now a good run in period is working as advertised. The owner is extremely happy with its operation & she has started the generator only twice in this period. Well, she hasn't started the generator, the ATESS HPS inverter has started the generator when it has needed to. The integration is perfect in that the HPS inverter will send a Dry contact signal to start the generator as well as when to stop the generator. The biggest challenge has been to keep the Generator battery charged because of the lack of run time. This is based on a SoC value as supplied from the FreedomWon batteries. 

Apart from a coil that died in the ATS switch that pairs Generator & Grid integration the installation ran very smoothly. We managed to get hold of ATESS Support & a new Contactor was shipped & received in 3 days. We decided to not replace the entire Contactor we replaced just the Coil. 

The Coil was damaged due to a Grid spike before we had commissioned. I must thank @BritishRacingGreenhe was my support engineer on this project & I must admit without his massive contribution we would have not had such a successful outcome. 

Now for the big question: ATESS HPS vs the Sunsynk 50kW HV machine? 

My very analytical & humble opinion: The Sunsynk is a good machine, however, if you encounter a technical issue onsite & need to get assessed Sunsynk will insist on you bringing the machine in for assessment & RMA. I have encountered this with a 12kW Machine & the entire repair and assessment took 6 weeks. The Sunsynk machine exposes nothing to the user or engineer. 

The ATESS on the other hand has all of its guts exposed and with a technician & seasoned  support Engineer like @BritishRacingGreenyou can basically have site support & repair onsite without the need to move this machine. Ill also throw into the mix that a Sunsynk can be removed because it weighs a lot less. An ATESS HPS100 is close to a ton in weight. 

But this was a very challenging but very rewarding project & we already have more of these ATESS installations projects in the pipeline. 

Here are pics of the Contactor that got destroyed and the Coil that was replaced. The contactors do have surge protection but this was not engaged at the time of the event as the equipment was not fully commissioned yet. The Contactor was shipped to us under warranty at no cost. 

58 minutes ago, Steve87 said:

So all in all this ATESS with now a good run in period is working as advertised. The owner is extremely happy with its operation & she has started the generator only twice in this period. Well, she hasn't started the generator, the ATESS HPS inverter has started the generator when it has needed to. The integration is perfect in that the HPS inverter will send a Dry contact signal to start the generator as well as when to stop the generator. The biggest challenge has been to keep the Generator battery charged because of the lack of run time. This is based on a SoC value as supplied from the FreedomWon batteries. 

Apart from a coil that died in the ATS switch that pairs Generator & Grid integration the installation ran very smoothly. We managed to get hold of ATESS Support & a new Contactor was shipped & received in 3 days. We decided to not replace the entire Contactor we replaced just the Coil. 

The Coil was damaged due to a Grid spike before we had commissioned. I must thank @BritishRacingGreenhe was my support engineer on this project & I must admit without his massive contribution we would have not had such a successful outcome. 

Now for the big question: ATESS HPS vs the Sunsynk 50kW HV machine? 

My very analytical & humble opinion: The Sunsynk is a good machine, however, if you encounter a technical issue onsite & need to get assessed Sunsynk will insist on you bringing the machine in for assessment & RMA. I have encountered this with a 12kW Machine & the entire repair and assessment took 6 weeks. The Sunsynk machine exposes nothing to the user or engineer. 

The ATESS on the other hand has all of its guts exposed and with a technician & seasoned  support Engineer like @BritishRacingGreenyou can basically have site support & repair onsite without the need to move this machine. Ill also throw into the mix that a Sunsynk can be removed because it weighs a lot less. An ATESS HPS100 is close to a ton in weight. 

But this was a very challenging but very rewarding project & we already have more of these ATESS installations projects in the pipeline. 

Here are pics of the Contactor that got destroyed and the Coil that was replaced. The contactors do have surge protection but this was not engaged at the time of the event as the equipment was not fully commissioned yet. The Contactor was shipped to us under warranty at no cost. 

Thanks for the nice detail. Is there no grid charging to keep the genny starting battery fully charged? 

Nice @Steve87 looking good gee gas pappa good to have a electronic fundi like @BritishRacingGreen on speed dial. Great install guys👌👌👌

14 hours ago, Steve87 said:

So all in all this ATESS with now a good run in period is working as advertised. The owner is extremely happy with its operation & she has started the generator only twice in this period. Well, she hasn't started the generator, the ATESS HPS inverter has started the generator when it has needed to. The integration is perfect in that the HPS inverter will send a Dry contact signal to start the generator as well as when to stop the generator. The biggest challenge has been to keep the Generator battery charged because of the lack of run time. This is based on a SoC value as supplied from the FreedomWon batteries. 

Apart from a coil that died in the ATS switch that pairs Generator & Grid integration the installation ran very smoothly. We managed to get hold of ATESS Support & a new Contactor was shipped & received in 3 days. We decided to not replace the entire Contactor we replaced just the Coil. 

The Coil was damaged due to a Grid spike before we had commissioned. I must thank @BritishRacingGreenhe was my support engineer on this project & I must admit without his massive contribution we would have not had such a successful outcome. 

Now for the big question: ATESS HPS vs the Sunsynk 50kW HV machine? 

My very analytical & humble opinion: The Sunsynk is a good machine, however, if you encounter a technical issue onsite & need to get assessed Sunsynk will insist on you bringing the machine in for assessment & RMA. I have encountered this with a 12kW Machine & the entire repair and assessment took 6 weeks. The Sunsynk machine exposes nothing to the user or engineer. 

The ATESS on the other hand has all of its guts exposed and with a technician & seasoned  support Engineer like @BritishRacingGreenyou can basically have site support & repair onsite without the need to move this machine. Ill also throw into the mix that a Sunsynk can be removed because it weighs a lot less. An ATESS HPS100 is close to a ton in weight. 

But this was a very challenging but very rewarding project & we already have more of these ATESS installations projects in the pipeline. 

Here are pics of the Contactor that got destroyed and the Coil that was replaced. The contactors do have surge protection but this was not engaged at the time of the event as the equipment was not fully commissioned yet. The Contactor was shipped to us under warranty at no cost. 

New to the discipline of renewable energy, that was just a great exposure I had  scaling up from the relative  'comfort'  of the MAX7. 2 to the likes of a 100kW workhorse. I must say I am impressed by the stability and performance of these ATESS machines. And especially considering the harsh distributed load network its exposed to, not only in terms of high power, but also 'dirty' loads in terms of multiple water pumps switching heavy energy at random periods. 

The 400A grid contactor was interesting. The coil was  damaged by a nasty incoming surge when Eskom repaired an incoming cable. I found it particularly unlikely that a contactor coil will perish under surge.  But this, like other heavy duty dc and ac coils, is not your typical coil. It has an economiser circuit, in order to reduce coil power when energized. A contactor or relay will typically require an amount of energy to energize the actuator, but once energized it actually requires a smaller percentage of energy to keep it energized.  For small relays this is not an issue, but to keep a large contactor energized at full power will heat up the coil, and use unneccessary power.  Medium relays/contactor may use a simple power resistor to reduce power via a auxiliary contact. But with this large beast a power resistor will get too hot. So here they untroduce a PWM control circuit switching the coil via a power mosfet or igbt. So in our case the incoming surge destroyed the electronics inside the contactor. 

Fortunately these type of contactors have a dockable coil cartridge or coil pack, which is replaceable. 

Edited August 6, 20232 yr by BritishRacingGreen

18 minutes ago, BritishRacingGreen said:

New to the discipline of renewable energy, that was just a great exposure I had  scaling up from the relative  'comfort'  of the MAX7. 2 to the likes of a 100kW workhorse. I must say I am impressed by the stability and performance of these ATESS machines. And especially considering the harsh distributed load network its exposed to, not only in terms of high power, but also 'dirty' loads in terms of multiple water pumps switching heavy energy at random periods. 

The 400A grid contactor was interesting. The coil was  damaged by a nasty incoming surge when Eskom repaired an incoming cable. I found it particularly unlikely that a contactor coil will perish under surge.  But this, like other heavy duty dc and ac coils, is not your typical coil. It has an economiser circuit, in order to reduce coil power when energized. A contactor or relay will typically require an amount of energy to energize the actuator, but once energized it actually requires a smaller percentage of energy to keep it energized.  For small relays this is not an issue, but to keep a large contactor energized at full power will heat up the coil, and use unneccessary power.  Medium relays/contactor may use a simple power resistor to reduce power via a auxiliary contact. But with this large beast a power resistor will get too hot. So here they untroduce a PWM control circuit switching the coil via a power mosfet or igbt. So in our case the incoming surge destroyed the electronics inside the contactor. 

Fortunately these type of contactors have a dockable coil cartridge or coil pack, which is replaceable. 

These contactors are very expensive, and so you even get a service kit for it, containing, amongst other, a set of contacts. This makes this device servicable, pretty cool I think. 

Edited August 6, 20232 yr by BritishRacingGreen

32 minutes ago, BritishRacingGreen said:

These contactors are very expensive, and so you even get a service kit for it, containing, amongst other, a set of contacts. This makes this device servicable, pretty cool I think. 

Thanks for the pictures and description of the contractors and related gadgets. 

This was the standard way to maintain say over 7.5kW contractors decades ago. Thus good to see the throw away age had not caught up at the higher rating of switch gear. 

This unit is of interest to see the economy PWM on the coil. Decades ago it was common using a resistor for DC but in the same time frame I have never seen it being used for AC. Once the movable portion of the contactor closed the iron core the current dropped so low I guess it was not needed. 

Hey it was very long ago that one maintained these kinds of switch gear. 

Just to share a typical DC contactor in single polarity. Note the massive arc shield at the top and the large coil needed to get enough turns on to get enough power/speed at a low power consumption. Major difference to AC contractors. 

 

Edited August 6, 20232 yr by Scorp007

This is a monster...😂😂😂 But this is why the ATESS inspires confidence. The entire architecture & machine is exposed. It's also a true hybrid in that it can Grid feed excess solar to the non essentials with zero export. The only draw back but then again this comes as a trade off. The idle consumption power is at 700W, but this is the price you pay for a large transformer architecture. The HPS model is the popular model at the moment but they have PCS models that start where the HPS left off. They range from 200kW up to 630kW meaning you can parallel 4 of them to reach 2.5MW. 

But then for simplicity they remove the MPPT as well as the switch gear & then you need some extras to get going. However, this to me makes a lot of sense. It then becomes modular very similar to a Victron machine on massive steroids. But this type of rugged architecture & exposure I see as a massive plus Because an investment like this cannot be made recurring so one needs to buy right the first time & then just like the old days this machine can be serviceable with our own support engineers. 

Out of interest if we had to purchase that LG Contactor off shelf out of warranty that would have incurred a cost of R12.5k. 

This site has just been updated & we have experienced an issue with a weak cell in one of the 40/32HV FreedomWon batteries. One of the batteries has been left online this weekend & the beauty of the ATESS is that it can run on a single lower capacity battery. The FreedomWon 40/32HV has a max discharge rate of 150A which equates to 60kW discharge spike but continuous discharge is 1C. The owner of this farm has also taken advantage of the lower Solar PV prices & has just purchased another 23kW of PV modules so that will upgrade to the entire array to 63kW of LONGi Modules. 

But on the subject of the FreedomWon battery we have a cell that is pulling the rest of the pack down. The fundamentals of building a 48V battery requires 16 or 15 cells depending on your architecture. The 40/32HV has a staggering 128 cells. Imagine trying to to balance 128 cells. 

I will say this again, support is a massive part of a solar system. This battery costs in the region of R250k. I have facilitated the investigation by FreedomWon into the problem but we have a cell that has a substantially lower Voltage to the others. They will meet with us at the site with an Engineer to address the issue. 

We have a Cell Delta of 0.500V on this cell in comparison to the other cells. They did try some firmware upgrades but in my opinion you cannot fix a hardware issue with firmware. 

To be continued...I will definitely report back because if me as an installer will sell an asset of this value then we must hold such a battery manufacturer to terms when they warranty such a product. 

Let's test to see if FreedomWon's warranty is worth the paper it's written on. 

 

We have a Cell Delta of 0.500V on this cell in comparison to the other cells.

The Delta is way off at 500mv if i am not mistaken acceptable Delta should be 5mv~ 7mv for lfp. I will wait in anticipation as how FW will handle this like you said you won't fix that Delta with firmware. Its the high and low knees where you will find out how good your top balance is and how well your cells match. Hopefully it will have a good outcome as i have and will use quite a few of the FW Lite versions.