Schneider XW Pro Enhanced Grid Support issues

[romangeek]

I have installed a Schneider XW Pro Inverter with their MPPT 100 600 charger and Lithium Smart batteries. I have the latest firmware. The unit works great from a performance point of view, seems quite efficient based upon heat it dissipates and is incredible at handling surges! I have a 6 HP 240 V compressor and it starts it without the slightest hesitation. However, I am also selling to the grid. I wanted to do their Enhanced Grid Support. Meaning… keep batteries charged, use the power from the PV to run the house and sell any extra to the grid. I scoured the documents and the WEB and could not get information for it to work properly… meaning: It would only sell to the grid at the rate of the “max sell amps”! The impact of which was to discharge the battery at a high rate until the batter SOC (or voltage.. depending on mode) would be reached and then it would stop using energy from the PV, the house would be fed from the grid, the battery would then be recharged to above the SOC limit and then the cycle would start all over again! Constant large current cycling of the battery about every 55 seconds.

I called technical support multiple times and all they gave me was the manual information and said it should work… but it did not.

In searching the WEB, I found multiple people encountered this problem but no one including Schneider had a solution! Well, I stumbled upon the solution… They say that the Grid Support voltage should be set to 64 Volts in order to enable the Enhanced mode. That does not work. I have verified this on my system and the exact system of a friend of mine (we bought same equip. at the same time).

The answer is to run it in the SOC mode but have the Grid Support voltage at the float voltage of the charge controller! Then it works beautifully!!! Just a note: the charger settings on the MPPT must be the same values as on the Inverter.

I wasted about 25 hours with this issue and Schneider was no help at all. I believe that at this point I understand the system better than their technical support people.

If any of you struggled with the same issue… I hope this will help you!

 

[dougbert]

@GXMnow and @400bird have long posts on these issues

I also have an XW Pro, but do NOT use Netmetering so I do not sell to the grid, but I do have Grid assist as my backup "generator"

Adding storage to my Enphase system

I am still fairly new on the forum, tried to answer a few questions as I asked some, and have been talking about my plans and purchases. I figure this is the right place to talk about what I am doing and where it is going. My existing system is a very typical Enphase setup. I have 2 arrays of 8...

diysolarforum.com

 

[BentleyJ]

The answer is to run it in the SOC mode but have the Grid Support voltage at the float voltage of the charge controller! Then it works beautifully!!! Just a note: the charger settings on the MPPT must be the same values as on the Inverter.

Interesting behavior coming from the XW Pro. I know you did mention that the problem was the same with both SoC and Voltage mode. Does this mean you turned off closed loop BMS communications (maybe even disconnected the cable) and still the XW Pro did not function in Enhanced Mode per Pg 84 of the manual?
I'm sure you tried everything, was just thinking that there are SOO many reported problems with closed loop communications and its across several brands. Its really odd for the XW to simply not follow protocol unless the firmware is corrupted or somehow the BMS communication overrides or interferes with certain modes.

 

[romangeek]

According to the release notes for the latest firmware, there are issues with the Enhanced GS. However, the give a "workaround".. which does not work!
I am still using closed loop SOC control, however, they still use voltages to do the actual control of how much power they take from the DC bus and how much they export after supporting the house loads. So what one would think is a completely SOC-based control is not so... it is a hybrid mode. Once the magic trick is known, mainly having the Grid Support voltage be the same as the Float voltage then it works magically. All their instructions say to have it not at Float but at a magic number "64". When I did that it just kept oscillating with the high discharge/charge cycles.

 

[MrM1]

How balanced are your loads? I found with the SW, balancer loads was critical to proper grid interactivity function.

The more things that you can run 240v the better.

 

[romangeek]

They are quite balanced. The issues is the firmware has some bugs related Advance GS... they even say so in the release notes. What I can't believe is that they would release the firmware with this bug! After all, this is a hybrid inverter and most people buying it would probably be interested in selling back to the grid until battery prices come down.

 

[WW5M_Bill]

I'm wondering if you have figured all this out. I have talked with Schneider in the past and just was told to read the book. My system has been in operation since fall of 2014. I have 2 of the older XW6048's - I have 7 kw of PV and 3 midnite solar classic 150 charger controllers. My battery bank has been 440ah of US battery wet cells. They are almost 5 years old now and I have a LiFePo4 setup which consists of 9 100ah EG4-LL batteries
I will be installing soon. Over the past 9 years I have run my XW's in sell mode and I am grid tied. I don't have a separate meter for solar. During peak PV output from 10 am to 3 pm, I get anywhere from 3 kwh to 39 kwh off my panels depending on weather conditions. So energy generated during the middle of the day gets exported to the grid(for which I am not compensated). I did this way because I figured the batteries would last longer in float mode.

With the upcoming installation of the EG4's I realized with the increased capacity (36 kw usable) I should be able to utilize them over night to power some of my loads. So I have started experimenting. First thing I learned is was the LBCO (low battery cutoff voltage) needed to be a minimum of 4 volts below my grid support voltage. I currently have my LBCO set at 44 volts and my grid support voltage at 48.1 volts which is
right at the 50% depth of discharge of the battery. I also set my sell amps to 5. This allows me to send approximately 1 kw of energy to the house
24 hours a day. Well currently until about midnite or so when my batteries are at 50% at which point I stop selling until next morning where
it starts charging the batteries again. This may be a compromise, but its better than running in float mode where most of the energy is sent to the house between 10 and 3 pm. I will be installing a power monitoring system to monitor my 24 hour usage so I can tweek my sell amps. Ideally I would like to install CT's on my main incoming and have a PLC program of sorts to adjust the sell amperage to keep incoming amps as close to zero as possible. My situation is different because my main incoming is at house panel and my solar all runs through my shop and backfeeds the house 75 ft away. Has anyone else tried doing this? Also my XW-6048 are older than the newer 6848 - not sure what software changes were made on the newer units. I do have the latest firmware in my inverters. Is anyone else doing this?

 

[RCinFLA]

With AC coupling, inverter will not allow battery to be fully charged. A fully charged battery internal impedance rises limiting the ability to absorb any AC coupled back feed into battery. It can push up DC input voltage to a level that exceeds maximum allowed inverter DC input voltage causing inverter to shut down to protect itself.

You might think this is a 'don't care' when grid feeding excess PV AC coupled power, but you never know when grid might collapse. You could be back feeding to grid with AC coupled PV power at a good amount of power then grid drops. Battery must be able to absorb the excess PV power until GT inverter output is reduced. With freq shifting this can take several seconds. If battery is fully charged this is enough time to cause DC input voltage to exceed maximum allowed voltage. Battery cable resistance aggravates this further, allowing inverter DC input to rise above the actual battery clamping voltage.

HF AIO inverters have direct hardware control on their internal PV SCC so they can near instantly modulate PV power delivered to HV DC bus. However, HF AIO inverter have another issue with battery to HV DC converter power flow direction switchover time to change between power output delivery to HV DC bus required to produce AC output power from battery and battery charging reverse power mode.

AC coupling on HF AIO inverter is very dicey. If there is excess AC coupled PV power it can quickly overvoltage HV DC bus, damaging inverter. SolArk and Deye HF inverters have a very large bank of HV DC capacitors to help absorb momentary back surge power. They also recommend feeding AC coupled inverter in through Gen AC input so they can use the pass-through relay to immediately disconnect from GT inverter if they get in trouble with excess AC coupled PV power.

 

[romangeek]

WW5M_Bill, good to hear about your experience. I am not familiar with the older Schneider but I like the XW Pro… and I will like it more when they fix the firmware!

In my case I only have two EG4-LL batteries which also had firmware issues until recently… but they are working well with the Schneider now. Since batteries are the expensive part, I decided to go with the minimum and export to the grid for Net-metering (use the grid as a battery). I also wanted to always have a full battery for when power goes down… and it does here.

I don’t know about your older Schneider and if supports the “Enhanced Grid support”? Once I figured out the settings, it actually works very well. The battery gets used only for small amounts of time such as when a big load first comes on or when a cloud suddenly passes to block the PV. It takes time for the algorithm in the inverter to rebalance the power and so the battery comes into play… but never even changes a single percent on the SOC meter. At that kind of discharge/charge I should be good for about a million cycles according to the battery chart.

I am not sure I understood correctly, but you are not being credited for moving power to the grid??



Also, I should mention that my PV is all DC… two strings of ~500 V at 11 amps. I have ground-mounted arrays which are angled 35 degrees from solar south… one east and one west. This way I get a better spread through the day and I do not overwhelm my charge controller during solar noon, which can only utilize 5KW anyway.

 

[RCinFLA]

Since batteries are the expensive part, I decided to go with the minimum

Common mistake. You need a large enough AH battery to take possible back surge charging current while freq adjust power cutback is in process on GT inverters.

Believe Xantrex recommends at least 100 AH per kW of PV GT power but that depends on battery type and condition. 1 kW is going to push about 20 amps to battery, 5 kW will be 100 amps.

LPF's can take the peak surge current better but you still have to worry about overvoltage tripping inverter max DC input which is like 64-65 vdc.

 

[romangeek]

The two batteries together are 200 AH

 

[WW5M_Bill]

WW5M_Bill, good to hear about your experience. I am not familiar with the older Schneider but I like the XW Pro… and I will like it more when they fix the firmware!

In my case I only have two EG4-LL batteries which also had firmware issues until recently… but they are working well with the Schneider now. Since batteries are the expensive part, I decided to go with the minimum and export to the grid for Net-metering (use the grid as a battery). I also wanted to always have a full battery for when power goes down… and it does here.

I don’t know about your older Schneider and if supports the “Enhanced Grid support”? Once I figured out the settings, it actually works very well. The battery gets used only for small amounts of time such as when a big load first comes on or when a cloud suddenly passes to block the PV. It takes time for the algorithm in the inverter to rebalance the power and so the battery comes into play… but never even changes a single percent on the SOC meter. At that kind of discharge/charge I should be good for about a million cycles according to the battery chart.

I am not sure I understood correctly, but you are not being credited for moving power to the grid??



Also, I should mention that my PV is all DC… two strings of ~500 V at 11 amps. I have ground-mounted arrays which are angled 35 degrees from solar south… one east and one west. This way I get a better spread through the day and I do not overwhelm my charge controller during solar noon, which can only utilize 5KW anyway.

Romangeek,

Yes that is correct I dont get compensation for what I send to grid. When batteries were floating I would get a lot of energy during the middle of the day. I know for fact I wasnt using it all especially in Fall, Winter and Spring. Summer AC loads used a lot. I'll have to look into the enhanced grid support. I believe it has a mode where it identifies the loads and will match them, but I'm not sure if it's just my home loads or the it may be seeing my neighbors. So for write now a kw an hour is where I set it. Thats 24 kw over a days time and should impact my electric bill in a positive way.

I will definitely be getting ct's and a way to read them to see what my power usage is. I am thinking about the Emporia unit that everyone on this forum raves about. Back when I installed my system there wasn't many charger controllers that went up to 600 vdc. I am limited to 150 volts with my midnite classics. They work good for now so I'll stay with them.

 

[BooneMtn]

@GXMnow and @400bird have long posts on these issues

I also have an XW Pro, but do NOT use Netmetering so I do not sell to the grid, but I do have Grid assist as my backup "generator"

Adding storage to my Enphase system

I am still fairly new on the forum, tried to answer a few questions as I asked some, and have been talking about my plans and purchases. I figure this is the right place to talk about what I am doing and where it is going. My existing system is a very typical Enphase setup. I have 2 arrays of 8...

diysolarforum.com

I'm about to buy a 2 XW Pros and won't sell to grid but would like grid power as backup. When you say "my backup generator" does that mean you wire the grid AC to your generator terminals in the inverter? I've seen many on forum say wiring grid AC into inverter will back feed small amounts to grid even when settings are set to not do that. Since utility companies might be able to detect this I want to avoid feeding back to grid. Ideas? thanks

 

[pvdude]

I have not found any way to stop a tiny amount of energy "leaking" back to the grid.
On my system, sell is disabled, "Sell amps" is set to zero.
Grid support is enabled.

My system is configured to use the PV to power the loads, through the inverters.
When there is not enough Sun, the inverters transition to powering loads from the grid.
The inverters source power from the batteries for a few seconds while transitioning, otherwise the batteries are always in "standby".

I installed a Vertiv Liebert TDU-4000RTL630 4kva step down transformer as an experiment to see if balancing the loads would reduce leakage to the grid.

https://www.anixter.com/en_us/products/TDU-4000RTL630/VERTIV/Miscellaneous/p/9999808

Nope.
All the small 120vac loads are plugged into the TDU.
The TDU is connected to the inverter 240 output.
Thus, the inverters see a balanced 240 for all loads.

However, the amount of leakage is so tiny, it is lost in the noise of other switching, sags, surges from the other users connected to the grid pole pig.

Also, I'm not sure that the "Grid Energy (Sell) numbers reported by the Schneider SW are accurate or valid.
Some of the Schneider SW is flawed.

 

[BooneMtn]

Makes sense given how small the leakage is. thanks

 

[BooneMtn]

I have not found any way to stop a tiny amount of energy "leaking" back to the grid.
On my system, sell is disabled, "Sell amps" is set to zero.
Grid support is enabled.

My system is configured to use the PV to power the loads, through the inverters.
When there is not enough Sun, the inverters transition to powering loads from the grid.
The inverters source power from the batteries for a few seconds while transitioning, otherwise the batteries are always in "standby".

I installed a Vertiv Liebert TDU-4000RTL630 4kva step down transformer as an experiment to see if balancing the loads would reduce leakage to the grid.

https://www.anixter.com/en_us/products/TDU-4000RTL630/VERTIV/Miscellaneous/p/9999808

Nope.
All the small 120vac loads are plugged into the TDU.
The TDU is connected to the inverter 240 output.
Thus, the inverters see a balanced 240 for all loads.

However, the amount of leakage is so tiny, it is lost in the noise of other switching, sags, surges from the other users connected to the grid pole pig.

Also, I'm not sure that the "Grid Energy (Sell) numbers reported by the Schneider SW are accurate or valid.
Some of the Schneider SW is flawed.
View attachment 158811
View attachment 158812

What would the settings be if you want to transition at night to the batteries first until SOC down to 20% then take power from grid?

 

[pvdude]

What would the settings be if you want to transition at night to the batteries first until SOC down to 20% then take power from grid?

Not sure, I don't do it exactly that way.
Mine seems to ignore the SOC setting, and just uses the voltage.
(Probably because I have charging shut off.)
When my inverters draw the batteries down to near "grid support voltage: 54vdc", the inverters switch to the grid.
I don't remember why 54vdc is the value I used.
(I am using FLA batteries, almost no one does that any more.)

Also, I do not use the inverters to charge the batteries, charging is disabled.
The batteries are charged by the Schneider charge controllers.
The battery manufacturer ( https://rollsbattery.com/ ) did not want me to use the two-stage inverter chargers,
as the charge controllers provide three-stage charging, which they like better.

So in your case, adjusting the "grid support voltage" might be a simple way to regulate
when the grid is used, as the batteries discharge to the support voltage.
You would have to experiment to find the SOC value desired.
But you will probably have a different battery & charging configuration, so there will be other ways to do what you want.

However, there are about 9487376 ways to configure the Schneider SW, and I fear it.
So I just try for the most simple configuration, and so far, that works.

 

[dougbert]

I'm about to buy a 2 XW Pros and won't sell to grid but would like grid power as backup. When you say "my backup generator" does that mean you wire the grid AC to your generator terminals in the inverter? I've seen many on forum say wiring grid AC into inverter will back feed small amounts to grid even when settings are set to not do that. Since utility companies might be able to detect this I want to avoid feeding back to grid. Ideas? thanks

grid power is connected to AC 1 in

I use the grid after too many cloudy/raining/snowy days and my battery is low. One option I do is switch the grid on in BYPASS mode to run my house loads and then let the solar arrays recharge the battery when they get some sun

my battery lasts about 2.5 days, more if I cut loads

 

[n2aws]

Romangeek,

Yes that is correct I dont get compensation for what I send to grid. When batteries were floating I would get a lot of energy during the middle of the day. I know for fact I wasnt using it all especially in Fall, Winter and Spring. Summer AC loads used a lot. I'll have to look into the enhanced grid support. I believe it has a mode where it identifies the loads and will match them, but I'm not sure if it's just my home loads or the it may be seeing my neighbors. So for write now a kw an hour is where I set it. Thats 24 kw over a days time and should impact my electric bill in a positive way.

I will definitely be getting ct's and a way to read them to see what my power usage is. I am thinking about the Emporia unit that everyone on this forum raves about. Back when I installed my system there wasn't many charger controllers that went up to 600 vdc. I am limited to 150 volts with my midnite classics. They work good for now so I'll stay with them.

I just saw this. Instead of spending the money on the emporia, you may want to consider a wattnode with CT's. It can talk to the insight home/facilty, and enable your XW inverters to do "zero sell" or "grid zero", by curtailing the XW's output when selling excess to zero out the meter without sending power back to the grid. It also supports modbus over TCP (as does the insight home) so, you can poll them to graph usage.

 

[Roman59]

I have installed a Schneider XW Pro Inverter with their MPPT 100 600 charger and Lithium Smart batteries. I have the latest firmware. The unit works great from a performance point of view, seems quite efficient based upon heat it dissipates and is incredible at handling surges! I have a 6 HP 240 V compressor and it starts it without the slightest hesitation. However, I am also selling to the grid. I wanted to do their Enhanced Grid Support. Meaning… keep batteries charged, use the power from the PV to run the house and sell any extra to the grid. I scoured the documents and the WEB and could not get information for it to work properly… meaning: It would only sell to the grid at the rate of the “max sell amps”! The impact of which was to discharge the battery at a high rate until the batter SOC (or voltage.. depending on mode) would be reached and then it would stop using energy from the PV, the house would be fed from the grid, the battery would then be recharged to above the SOC limit and then the cycle would start all over again! Constant large current cycling of the battery about every 55 seconds.

I called technical support multiple times and all they gave me was the manual information and said it should work… but it did not.

In searching the WEB, I found multiple people encountered this problem but no one including Schneider had a solution! Well, I stumbled upon the solution… They say that the Grid Support voltage should be set to 64 Volts in order to enable the Enhanced mode. That does not work. I have verified this on my system and the exact system of a friend of mine (we bought same equip. at the same time).

The answer is to run it in the SOC mode but have the Grid Support voltage at the float voltage of the charge controller! Then it works beautifully!!! Just a note: the charger settings on the MPPT must be the same values as on the Inverter.

I wasted about 25 hours with this issue and Schneider was no help at all. I believe that at this point I understand the system better than their technical support people.

If any of you struggled with the same issue… I hope this will help you!

I was reading your problem and how did you solve it, very well done...I wonder if to activate the SOC mode in the inverter you have to have the batteries in close loop or can it be done in open loop?...I have the problem that when I sell to the grid it pulls the batteries... I have them in open loop and the grid support in 64V... thanks