Hybrid Offgrid ignore Load during charging state.

[andydarwin]

I Installed 11000KVA hybrid Offgrid Techfine inverter with 18pcs 555wp Longi Solar Panels. I also have 52V 280Ah x 2 Battery with BMS.

everything run and no error. But I annoyed by the system setting..That I can not have tHe PV Power Load First then excess energy will be used to charge battery in "AC Mode" it can only do that in "DC modes "
does anybody experience samething ?
the system setting has these few function :
1. INPUT priority
SBU ( Utility will only be used if no solar and battery available )
SUB ( battery only used as a backup when both solar and Utility is not available)
2. the charging priority
BLU and LBU ( Battery Load Utility and Load Battery Utility as Output Priority )
3. charging source
SNU ( solar and electricity together)
CSO ( solar firsr, utility used only when solar not available)
OSO ( only Solar)
so What I do right now is the system will go to DC modes when Battery bms detected 70% SoC. and back to AC mode when Bms detected 25% Soc.
I set SBU,CSO and LBU..
what annoy me is.LBU doesnt works..so during charging state when Battery SoC is less than 70%, All PV power will be used to charge Battery and ignoring the Load. the load will take 100% from Grid. After 70% reached the inverter will Ignore Grid . all Load will be powered by Solar PV , if not enough it will consume Battery.
what I want is :
1. when Battery less than 70%, PV will prioritize load, if PV power is not enough then take from Grid, but if PV power is more,then charge the battery.
but this operation can only be done if I set to SUB mode + On grid Enabled. but doing so, even when the battery is 100%, the System will ignore Battery unless both Solar and grid is not Available...
does Anybody has Same problem with me ??
is this Techfine Inverter is Error...or It is common for all Hybrid inverter behave this way ???

 

[timselectric]

It's acting like an off grid AIO.
Are you sure it's a hybrid?
(Can it export to grid? )

 

[kommando]

11000KVA hybrid Offgrid Techfine inverter

There are two versions for sale on Alibaba, Grid tie hybrid and Offgrid. Offgrid cannot be hybrid by definition so the description was misleading.

 

[andydarwin]

well.. I can Set Grid On or Grid Off..

when I set the Grid On + SUB(Solar-Utility-Battery) power input + LBU output priority → PV will supply power to Load first then Battery then Grid. it works just what I want BUT .. it will Ignore power from Battery as long as there is still Grid connected.

then ,when I set the Grid On + turn SBU model (solar Battery Utility ) . the LBU doesnt work.. it will still do BLU ( Battery Load Utility ). it will use PV to power the Load only IF the charging current is Higher than Maximum current Set..

when I set Grid Off... it doesnt matter LBU or BLU.. it will power the load using 100% Grid till Battery SOC is qualified for DC mode.

 

[timselectric]

All of the modes mentioned are typical for an off grid AIO.
Except for "LBU" and "BLU" . (Never heard of them before)
It's hard to guess what is going on, without knowing what type of unit it is.
If it is an off grid AIO, as I believe. Then the grid is only used in Passthrough.
So the AC charger and inverter share components and can't operate at the same time.
Not sure if that explains why it is doing what it is.

 

[andydarwin]

The Idea of Having Solar panel in the city is to Save Electricity Cost. So I want to Harvest as Much solar Energy as Possible..

so My ideal situation is. in the Morning till Afternoon when Solar Power is Strong, and Battery SoC is less than 90%,The Inverter will use PV to power the Load(house) first , and excess energy will be used for charging Battery.When PV energy is not enough to power Load ( let say cloudy ) it will add it from Utility (Grid).

then, at Night, when Battery already fully charged, it will use only Battery to power the House untill the Battery drop to SoC 20%,then it will switch back to Grid.

Does this request normal for offgrid inverter ? do other inverter has this Capability ??

what Annoy me with my current system is,
when SoC of Battery Less than 70% ( i set it ) , it will power Load using Utility (bypass) , and charge Battery from PV 100%.
and usually around 1Pm when Sun is strong，my Battery already fully Charged and Home doesnt need that much power. And I dont want to send the extra Power to Grid because Government wont pay me anything, I ended Wasted the Extra Energy from PV while I actually can use it for power my load during charging in the morning..

what I can do To trick it is : maybe Turn off My Grid MCB in the morning and turn it on at night. But by doing So, when The Load need more power in the morning while PV energy not enough it will take Power from battery while it still in Low SOC.



So.... do I asking for Normal capability of the Inverter ? or "Techfine inverter" behave strangely Bythemselves ??? or the technology doesnt exist yet ????
the technician keep telling me their inverter is not as intelligent as what i mentioned. also told me if I compare it to growatt then It my mistakes, growatt is the best of course they cant compete.

 

[timselectric]

My ideal situation is. in the Morning till Afternoon when Solar Power is Strong, and Battery SoC is less than 90%,The Inverter will use PV to power the Load(house) first , and excess energy will be used for charging Battery.

This is possible in SBU mode.

When PV energy is not enough to power Load ( let say cloudy ) it will add it from Utility (Grid).

This is possible in SUB mode.

then, at Night, when Battery already fully charged, it will use only Battery to power the House untill the Battery drop to SoC 20%,then it will switch back to Grid.

This is possible in SBU mode.

Does this request normal for offgrid inverter ?

Only if you switch between the different modes. Or have some type of 3rd-party automation to do it for you.

do other inverter has this Capability ??

Some hybrid AIO's have settings for switching between modes.
But they also require an agreement (contract and permitting) with the utility company.

 

[dinosaursolar]

Hi Andy,

Do you have a picture of your techfine inverter? I am looking to get 1 as well

 

[meetyg]

Interesting...
The only AIOs that I'm aware of that have LBU/BLU settings are MUST.

It would really be helpful if you send us a user manual or the exact model you have.

If your inverter is anything like my MUST PH18-PLUS, first disable "On-grid".
The working logic of this setting is simply stupid in my opinion and doesn't work well.

I'm not sure you can achieve what you want from these types of inverters. The more high end ones (Deye, Sunsink, Solar, etc...) have more flexibility and time of use settings.

Do you have a setting like "Solar power balance" (may be a different menu number)?


My MUST can actually blend AC power even when in SBU mode, if battery voltage is under the "back to battery" voltage setting.
It does this in a proportional manner to the delta between battery voltage and the "back to battery" setting.
So for example if the battery is close to (but slightly above) that voltage setting, it will still take some power from the battery, but not all the power needed to supplement the PV power. The rest it takes from the grid:


I'm not sure what the exact voltage I set for back to battery when this screenshot was taken, but it was something like 26.4v.

If battery voltage was under that setting, it will stop taking power from the battery and just blend PV and AC power.

In my opinion this is how a true hybrid should work!
But I was unaware of this capability at the time of buying the unit. I am not aware of any budget AIOs capable of doing this!
It's also not clearly documented by the user manual.
So it was an interesting surprise to me that it does this.

I am wondering of your inverter works in a similar way, since we both seem to have similar settings of grid-feedback and LBU/BLU priority.

BTW, my settings are SBU + BLU, OSO.

 

[andydarwin]

Hi Andy,

Do you have a picture of your techfine inverter? I am looking to get 1 as well

Here is my Set up.. ( sorry for messy cable)

I dont think Techfine is recommended.. I am not sure it has low efficiency because of the product or because I installed 11KVA but only using 3k power.

also it gives some electric shock back to the solar panel. it doesnt happen to My Growatt On grid inverter.

 

[andydarwin]

Interesting...
The only AIOs that I'm aware of that have LBU/BLU settings are MUST.

It would really be helpful if you send us a user manual or the exact model you have.

If your inverter is anything like my MUST PH18-PLUS, first disable "On-grid".
The working logic of this setting is simply stupid in my opinion and doesn't work well.

I'm not sure you can achieve what you want from these types of inverters. The more high end ones (Deye, Sunsink, Solar, etc...) have more flexibility and time of use settings.

Do you have a setting like "Solar power balance" (may be a different menu number)?
View attachment 229691

My MUST can actually blend AC power even when in SBU mode, if battery voltage is under the "back to battery" voltage setting.
It does this in a proportional manner to the delta between battery voltage and the "back to battery" setting.
So for example if the battery is close to (but slightly above) that voltage setting, it will still take some power from the battery, but not all the power needed to supplement the PV power. The rest it takes from the grid:
View attachment 229692

I'm not sure what the exact voltage I set for back to battery when this screenshot was taken, but it was something like 26.4v.

If battery voltage was under that setting, it will stop taking power from the battery and just blend PV and AC power.

In my opinion this is how a true hybrid should work!
But I was unaware of this capability at the time of buying the unit. I am not aware of any budget AIOs capable of doing this!
It's also not clearly documented by the user manual.
So it was an interesting surprise to me that it does this.

I am wondering of your inverter works in a similar way, since we both seem to have similar settings of grid-feedback and LBU/BLU priority.

BTW, my settings are SBU + BLU, OSO.

Nope.. my Inverter dont have this function..
if I set SBU ( Battery < 70%), Load will be powered by Grid 100%.. when battery >70%, the DC mode will active and Load will be powered By PV+ Battery.. No Option Using Grid..

but ,
when Battery < 20%, it will back powering Load by Grid. PV will not power Load unless Grid is turned off.

this is why I felt the inverter is stupid.. the LBU and BLU just doesnt works during SBU and grid disable.

the only way i can combine PV and Grid power to load is SuB + Grid enabled setting.

 

[dinosaursolar]

Here is my Set up.. ( sorry for messy cable)

I dont think Techfine is recommended.. I am not sure it has low efficiency because of the product or because I installed 11KVA but only using 3k power.

also it gives some electric shock back to the solar panel. it doesnt happen to My Growatt On grid inverter.

Thank you Andy

Good to know, still considering other options