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laurentiupitran avatar image
laurentiupitran asked

ESS system running with small PV energy but feed on grid?

hello everybody,

i m using an ESS system, three phase, 2X BYD batteries 10 kW; PV area 9,6 kW, 3 X Multiplus 5 kVA and Fronius Symo 10 kW.

satisfied with more than one year from the installation of system; monitoring for long time with separate devices from VICTRON - i m using also Color GX from Victron as part of system.

for attached pictures, in a cloudy day, at the moment with sun on sky we can see that my house is using energy from grid also and in the same time is injected energy into the grid, even batteries are near empty.

as the ESS system is configured to feed battery first is appear that is not so optimised to do this job , and need some attention .

Can someone from Victron specialist explain what can be the reason of those graphs ?

clear in the another hand, my system is configured with minim injection on grid, approximately 30 W, because in configuration with 0W injection is became more unstable and energy injected on grid is bigger.

thank you,

laurentiu

ESSgrid
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5 Answers
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @laurentiu.pitran@gmail.com

It looks like normal: on phase 1 most power is used, so the system allows the (Fronius) PV inverter to produce power, this is done equally over 3 phases. Your energy company grid meter (usually) measures a total value over all phases so it is not counted as feed-in.

about the short peaks: this is usually when a big load switches off, the system needs a second or two to reduce power output to get things back in balance.

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laurentiupitran avatar image
laurentiupitran answered ·

hello again,

hope that in first post is clear what i want to tell:

-positive part is energy used from grid

-negative part is energy injected to grid

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ejrossouw avatar image
ejrossouw answered ·

@laurentiu.pitran@gmail.com. Do you have a gridmeter et340 or similar? First thing I noticed is the grid setpoint for such a large system is rather low as Victron recommends larger so maybe change it to 100?. Secondly it seems to be L3 that has the largest spikes. Maybe those are aspects to look into. Makes sure all 3 inverters are on the the same firmware as a start. Do you have a diagram of your system? What is your installer's view on this?

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laurentiupitran avatar image
laurentiupitran answered ·


ejrossouw


First of all, need to remind that my system is a system with no injection in grid – due to the fact that regulators generally can t regulated zero value so well, I decided to allowed some energy going on the grid.

By personal experience, I was trying many values for energy going into the grid and is appear at this time that setting 20 W or 30 W is best stability of system.

I was purchasing at very beginning an ET340 with the scope that I can use it to measure consumption energy from a particular load, but is impossible if is connected at Color GX, due to the fact that ET can be used inside ESS system only in 3 modes that is not acceptable for my scope.

Regarding ET 340 I must sincerely tell you that is a great device, but as soon as can be connected inside ESS system only in 3 modes is not acceptable; but is really great as CARLO GAVAZZI is released a specific software for this device that is a complete one, except that can t be integrated as software in the ESS system – even for this fact is OK for me as I integrated ET in separate system to can measure energy.

Graf that we can observe is “naturally” from house consumption and is OK as soon as there is no limit of Multiplus overpassed.

Of course, all three Multiplus of system have same firmware inside; existing also an electric diagram for system also.

Personally I have best impression about my installer; at this point I think that can t spend too much time for me to make a fine tuning for a system how I desire ; just specified at the beginning of my first post that “”I m generally satisfied with my system”.

Due to the fact that I m not sure if my system as is it is MAXIMUM possible as performance, I initiate this topic with arguments that I have in my hands.


2 comments
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kolfleading avatar image kolfleading commented ·

Can you please share with us the name of the Carlo Gavazzi software package that you use to monitor the ET340? Thanks!

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laurentiupitran avatar image laurentiupitran kolfleading commented ·

hi,

Carlo Gavazzi software was released on May 2019; UCS-Release 6.2.5-08may2019 is name of this software.

new picture with injection on grid ....

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Rob Fijn avatar image
Rob Fijn answered ·

Hello Laurentiu, this could be to do with the fase compensation. Each fase is set to take this minimum power from the grid. See this part of the ESS live manual Chapter 7.1

https://www.victronenergy.com/live/ess:design-installation-manual#phase_compensation_-_further_information

I am curious to know what is changed when you set the grid feed in to 100 Watt as Ejrossouw already suggested.

Rob


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laurentiupitran avatar image laurentiupitran commented ·

hi Rob,

as soon as i set more then 30 W injection on gid, value going to grid is begin to increase so much,time to time is going more than 300 w with peaks to 1500 to 2000 w.

so, after many time i decide to adjust at the value already known; phase compensation is enabled.

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