dbus-fronius-smart-meter with Phase 1 Hack

⚠️ ⚠️ ⚠️ Work in Progress, not yet 100% ⚠️ ⚠️ ⚠️

⚠️ Only usable with a Single-Phase System, where the actual values of L2 and L3 doesn't matter for ESS ⚠️

This is a fork of the original dbus-fronius-smart-meter repository. I'm running ESS on a victron with a dedicated battery behind a fronius hybrid inverter with it's own battery. The subgrids inverter (victron multigrid) should take over supply of it's attached loads during nighttime to increase the runtime of the hybrids battery. With usual smart-meter readings this leads to both inverters / batteries trying to go up and down on their feed-in values, both trying to zero out consumption at the feed in point.


Schematic Layout to illustrate what subgrid means.

This script reads a fronius smartmeter from the inverts solar-api and manipulates the readings in the following way:

Value of L1 will be replaced with the actual consumption of the ESS subgrid - so ESS can cancel out that consumption.
When there is solar overhead available, the value L1 will be adjust to a virtual feedin, so ESS starts to charge the desired amount.
In either case, the original value of L1 is added to L2 and the artificial value "L4" is deducted from L2, so the overall consumption stays correct.
Currents then are recalculated to match the displayed power based on the original voltage.
It can be configured how much of available solar overheat the ESS should steal from the fronius hybrid ;)

Example One, Controlled discharge:

From dusk till dawn, the value presented as L1 will equal the victron inverters AC-IN Value. In this example ESS is working with a grid set point of 35 Watts, so a tiny bit of energy will always flow from the main-grid to the sub grid. ESS will feed in enough from it's own battery to satisfy it's own critical loads needs:


Controlled discharge from dusk till dawn

Example Two, Charge ESS first

In the config file, two values can be set: SolarOverheadShare and SolarOverheadLimit. In this Example, we want the ESS battery to charge first, because it is only capable of charging with ~ 450 Watts, so it should get precedence above the hybrid inverter who can charge with around 7000 Watts. Therefore, we configure SolarOverheadShare=1 (100%) and SolarOverheadLimit=600 (Watts).

100% of the available PV-Overhead will now be requested by ESS, first. This is achieved by setting L1 to a manipulated -600 so ESS will start to act and balance on it's AC-IN until L1 will reach about -150 and the battery charge rate 450 Watts. The script will take care to take the actual loads as well as actual available PV-Overhead into account and recalculate a proper L1 value every cycle.


Controlled charge, by manipulating L1 to simulate available PV-Overhead: L1 is set in a way that ESS is starting to charge and the hybrid inverter will favour it's loads, charging less on it's own battery

Example Three, Balance PV Overheat evenly

TODO: Description

2024-04-17 08:17:40,234 root INFO Target Point AC: 384.0
2024-04-17 08:17:40,391 root INFO pvOverheadShare configured to 0.1 with a limit of 600.0
2024-04-17 08:17:40,392 root INFO Hybrid Battery charge: 1046.0
2024-04-17 08:17:40,394 root INFO PV overhead available: 976.9999999999997
2024-04-17 08:17:40,395 root INFO AC Loads: 925.9862855782374
2024-04-17 08:17:40,397 root INFO Total available overhead: 1097.0137144217622
2024-04-17 08:17:40,417 root INFO Vic-Bat-Charge: 134.0
2024-04-17 08:17:40,419 root INFO Vic-Bat-Loads: 250.0
2024-04-17 08:17:40,420 root INFO Max power to sneak: 109.70137144217622
2024-04-17 08:17:40,422 root INFO Additional Charge required: -24.298628557823776
2024-04-17 08:17:40,423 root INFO Final InjectionValue: 24.298628557823776


*PV Overhead share of `0.1` (10%): L1 will be calculated in a way that ESS is charging with about 109 Watts after balancing for 20 Watts on the artifical L1 value.

Installation.

wget https://github.com/realdognose/dbus-fronius-smart-meter-with-phase1-injection/archive/refs/heads/main.zip
unzip main.zip "dbus-fronius-smart-meter-with-phase1-injection-main/*" -d /data
mv /data/dbus-fronius-smart-meter-with-phase1-injection-main /data/dbus-fronius-smart-meter-with-phase1-injection
chmod a+x /data/dbus-fronius-smart-meter-with-phase1-injection/install.sh
/data/dbus-fronius-smart-meter-with-phase1-injection/install.sh
rm main.zip

⚠️ Check configuration after that - because service is already installed an running and with wrong data you will spam the log-file

View log file

cat /data/log/dbus-fronius-smart-meter-with-phase1-injection/current.log

Change config.ini

Within the project there is a file /data/dbus-fronius-smart-meter-with-phase1-injection/config.ini. For details, read the comments in the config file. After changing the config, restart cerbo in order to apply new settings due to the service beeing restarted.

Note: After changing the config file, a device restart is required.

original description

For information about additional configuration, please view the original smart meter readout repository at: https://github.com/ayasystems/dbus-fronius-smart-meter

⚠️ ⚠️ ⚠️ Important ⚠️ ⚠️ ⚠️

This hack fixes the ESS not beeing able to determine it's required Feed-In when running behind a fronius hybrid inverter with a battery. In Order to apply the solar overheat distribution between the hybrids battery and the ESS battery, another script to visualize the hybrids battery in ESS is required:

See here: https://github.com/realdognose/dbus-fronius-hybrid-battery-visualisation

(The script to split up the hybrid inverter into regular PV-Inverter plus battery can be used without this phase manipulation script, but is a prerequisite of the solar distribution feature, because it is mandatory to know if the fronius battery is already charging.)