Energy Meter - measuring method

Question

question

Lukáš Svoboda asked May 18, '24

Energy Meter - measuring method

Hello, I found out that in Czechia grid billing is based on arithmetic sum of consumption of each of 3-phases. Later I found that there is likely only single Energy Meter that supports this measuring - ET340. The problem is it's sample rate is very poor - 2000ms. Is there a way how to possibly reconfigure other more advanced meters to work in my country?

Is there direct impact of Energy Meter to overall ESS performance? Are the data from EM used by Multipluses for regulating of it's performance or is it just information used by VRM/Cerbo? Anyhow I am frustrated that I have only two options:
a) get wrong data because of use of phase sum instead of arithmetic sum.
b) get wrong data because of very slow sampling rate of ET340.

Energy Meter

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2024-05-18T18:37:39Z

Duivert NL answered · May 18 at 06:37 PM

Is the newer EM 540 an option? Its 100ms

Data from energy meter is used by ess system, i also have 3 phase ESS with em540 and its a fast meter

1

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Lukáš Svoboda commented · May 19 at 10:09 AM

EM540 is fast - samples 100ms, but ET340 is the slowest of all of them, because it samples at 2000ms.

As far as I know EM5xx/EM3xx/EM24/ABB are not an option, because they all calculate overall performance by doing vector sum instead of arithmetic per phase sum. Unfortunately in Czechia is used the later method.

If I understand the difference correctly, the former calculation works in the way, that if you send 1kW to L1 while draining 2kW from L2 then, in Germany you are billed only for 1kWh, while in CZ you get billed for 2kW.

This makes signifficant difference when optimizing consumption and operation of system. I wonder whether there actually is a solution how to make this perform well in PV unfriendly countries such as CZ.

0 ·

Answer 2 · 2024-05-19T11:02:09Z

Duivert NL answered · May 19 at 11:02 AM

Ah i understand, then the EM540 is not an option… dont know if the new victron energy meter could work in your case: VM-3P75CT

2

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Lukáš Svoboda commented · May 19 at 11:40 AM

Unfortunately even this one uses the vectorization according to official manual. Maybe there might be some "unofficial" firmware as long this behaviour is not linked with hardware design.

0 ·

Duivert NL Lukáš Svoboda commented · May 19 at 11:47 AM

Maybe you can ask carlo gavazzi directly wich meters support your needed method of measurement?

0 ·

Answer 3 · 2024-05-30T11:12:59Z

kerbal answered · May 30 at 11:12 AM

There are different versions from the EM540.
Pls have a look at EM530_EM540_IM_USE.pdf (gavazziautomation.com)

1717067618645.png (99.6 KiB)

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question