Modbus Power Control (remotecontrol power)

In development - for advanced users - use at on own risk.

Currently, this section only applies to Solax GEN4 hybrid inverters. A section for GEN3 might be added later. This feature makes it possible to control the 'activepower' directly.

As we are still experimenting to find the proper controls that can be easily used by automations, the interfaces described below may still change. This may break automations based on these parameters.

Introduction: Active power notion

As we found no clear description of Solax Active Power, this sections describes our understanding, which may be wrong !

Without PV, Activepower seems to be the amount of power injected or extracted into/from the battery. Positive means charging, negative discharging. In general, with PV, Activepower seems to be:

Activepower = battery(_charge) - PV.

The total power balance can be expressed as:

battery(_charge) - PV + measured_power(_export) + house_load = 0

or

Activepower + measured_power(_export) + house_load = 0

or

Activepower = - measured_power(_export) - house_load

or

Activepower = grid(_import) - house_load

Conclusion: we can look at Activepower in 2 ways (both ways are correct):

Activepower = grid(_import) - house_load
Activepower = battery(_charge) - PV

In these formulas:

Battery(_charge) is positive for charge and negative for discharge
Measured_power(_export) is positive for grid export and negative for grid import power. Grid(_import) is the negative of this value
Active power is positive for charge and negative for discharge

House_load is not directly measured by the inverter, but it can be computed in 2 ways:

Including inverter losses: house_load = PV - measured_power(_export) - battery(_charge)
or alternatively without inverter losses: house_load = inverter_load - measured_power(_export)

Solax Gen4 approach

The Solax Gen4 inverters use a modbus write_multiple_registers command. On the Gen4, these actions are not stored in EEPROM, so they can be executed frequently. The integration hides this complexity and implements one button to trigger a single or repeated update(s). The action behind this button is configurable through 6 parameter entities.

With these parameters a power control dashboard card can be created:

Main trigger button

remotecontrol_trigger : button that triggers a new remotecontrol timeslot on the inverter. The behavior during this time slot is determined by a set of non-persistent parameter registers:

Parameter entities

remotecontrol_power_control: either "Disabled", "Enabled Power Control", "Enabled Grid Control" or "Enabled Battery Control" . Future values "Enabled Quantity Control" and "Enabled SOC Target Control" are not implemented yet. "Enabled Grid Control" and "Enabled Battery Control" are target values computed by the integration.
remotecontrol_set_type: Either "Set" or "Update". Only "Set" has been tested and seems to work for updates also.
remotecontrol_active_power: The target active power level. The current implementation will automatically limit the specified value into the range determined by the modbus registers active_power_lower and active_power_upper (readonly sensors that are updated by the inverter continuously).

When remotecontrol_power_control = Enabled Power Control is chosen, the target value refers to the battery interface where positive values will cause batteries to charge, negative values will make the batteries discharge. When the target is set to zero, in the presence of PV, the PV will go to the battery, the house load will come from the grid. If in addition to selecting this mode, remote_control_import_limit is set to Zero, the house load will come from PV and battery only.

When remotecontrol_power_control = Enabled Grid Control is chosen, the target value refers to the grid interface where positive values mean import, negative values mean export. When using this mode, make sure that remotecontrol_import_limit is set to a high enough value so that the import target can be reached.

When remotecontrol_power_control = Enabled Battery Control is chosen, the target value refers to the battery interface where positive values mean charge, negative values mean discharge. If target is set to zero, excess PV power will be sent to the grid.

remotecontrol_reactive_power: Only tested with a zero value. Similar to remote_control_active power. We recommend to leave this parameter untouched as we cannot provide any guidance.
remotecontrol_duration: The length of the time slot during which the remotecontrol_trigger action will work. This is expressed in seconds with a default of 20 seconds. Longer periods can be specified, but we recommend to consider the autorepeat function that will automatically retrigger the remote_control button after each polling cycle for longer period (remotecontrol_autorepeat_duration). The value of remotecontrol_duration should be at least 5 seconds longer that the specified polling rate (initial configuration of this integration). When the duration has expired (and there is no autorepeat active), the system will use the normal use mode and disregard the remotecontrol settings until the trigger button is activated again.
remotecontrol_import_limit: In Enabled Power Control mode and Enabled Battery Control mode, the Grid import or export level can vary with the house load and PV power. This parameter makes it possible to perform 'peak shaving', so that the import power can be limited to a defined max value. In Enabled Grid Control mode, this parameter has no sense as the import level is fixed. In this case, this parameter must be set to a high value.
remotecontrol_export_limit: (ATTENTION: not working as intended - removed) In Enabled Power Control mode and Enabled Battery Control mode, the Grid import or export level can vary with the house load and PV power. This parameter makes it possible to perform 'peak shaving', so that the export power can be limited to a defined max value. In Enabled Grid Control mode, this parameter has no sense as the export level is fixed. In this case, this parameter must be set to a high value.

Autorepeat function

remotecontrol_aurorepeat_duration: If zero, there will be no autorepeat. A non-zero value determines the time period over which the last remotecontrol_trigger command will be autorepeated. During each polling cycle, the values will be recomputed (e.g. taking house load into account in Enabled Grid Control mode). By using autorepeat, an energy managment automation can interact with the system at a slow rate, e.g. only once an hour, while the autorepeat can recompute the target every 5 seconds (if polling rate is 5 seconds) without interaction from the automation.

Before issuing a remotecontrol_trigger button activation, an automation should make sure that the other remotecontrol_* parameters have the correct values. This also applies to manual interactions with the remotecontrol_trigger button.

Emulation of self-use and feedin-priority modes

remotecontrol_active_power can also be used to emulate the standard self-use and feedin-priority modes:

self-use: choose Enabled Grid Control and set remotecontrol_active_power target to zero (0)
feedin_priority: choose Enabled Battery Control and set remotecontrol_active_power target to zero (0)

Example simple automations (for use during winter)

Remotecontrol active power control is typically used in scenarios with dynamic prices that may change every hour (e.g. day-ahead-prices).

Although remotecontrol can be triggered manually and autorepeated for the desired duration, it often makes sense to let an automation choose and activate the best remotecontrol active_power mode. The thresholds used by these automations can be configured through input_number entities.

Automation parameters

The example automations shown below use a couple of input_number declarations to be declared in config/configuration.yaml:

input_number:
  no_discharge_price_threshold:
    name: No discharge price threshold
    unit_of_measurement: €
    min: 0
    max: 0.50
    step: 0.001
  charge_price_threshold :
    name: Charge price threshold
    unit_of_measurement: €
    min: 0
    max: 0.5
    step: 0.001
  charge_duration :
    name: Charge duration
    unit_of_measurement: s
    min: 0
    max: 18000
    step: 3600
  target_soc :
    name: Target SOC
    unit_of_measurement: '%'
    min: 50
    max: 98
    step: 2

This can be displayed as:

Automation to force charge at very low import price

This example assumes that:

the current grid import price is determined by sensor 'sensor.xxx_consumption_price'
the target charge level is fixed at 2500W in this example

alias: Gridcontrol charge
description: ""
trigger:
  - platform: template
    value_template: >-
      {{states('sensor.ecopower_consumption_price') <
      states('input_number.charge_price_threshold')}}
condition:
  - condition: or
    conditions:
      - condition: state
        entity_id: select.solax_charger_use_mode
        state: Self Use Mode
      - condition: state
        entity_id: select.solax_charger_use_mode
        state: Feedin Priority
  - condition: template
    value_template: >-
      {{states('sensor.solax_battery_capacity') | float(10.0) <
      states('input_number.target_soc') | float(0) -2 }}
action:
  - service: number.set_value
    data:
      value: "2500"
    target:
      entity_id: number.solax_remotecontrol_active_power
  - service: select.select_option
    data:
      option: Enabled Grid Control
    target:
      entity_id: select.solax_remotecontrol_power_control
  - service: number.set_value
    data:
      value: "{{states('input_number.charge_duration')}}"
    target:
      entity_id: number.solax_remotecontrol_autorepeat_duration
  - service: button.press
    data: {}
    target:
      entity_id: button.solax_remotecontrol_trigger
mode: single

Automation to stop this forced Grid Charge

alias: Gridcontrol charge - Stop
description: ""
trigger:
  - platform: template
    value_template: >-
      {{states('sensor.solax_battery_capacity') >
      states('input_number.target_soc')}}
    enabled: true
  - platform: template
    value_template: >-
      {{states('sensor.ecopower_consumption_price') >
      states('input_number.charge_price_threshold')}}
    enabled: false
condition:
  - condition: or
    conditions:
      - condition: state
        entity_id: select.solax_remotecontrol_power_control
        state: Enabled Grid Control
      - condition: state
        entity_id: select.solax_remotecontrol_power_control
        state: Enabled Power Control
action:
  - service: select.select_option
    data:
      option: Enabled Battery Control
    target:
      entity_id:
        - select.solax_remotecontrol_power_control
  - service: number.set_value
    data:
      value: "0"
    target:
      entity_id: number.solax_remotecontrol_active_power
  - service: number.set_value
    data:
      value: "3500"
    target:
      entity_id: number.solax_remotecontrol_autorepeat_duration
  - service: button.press
    data: {}
    target:
      entity_id: button.solax_remotecontrol_trigger
mode: single

Automation to stop discharge at reasonably low import price (Houseload from Grid - Feedin Priority)

Similar assumptions as above. This automation will activate an equivalent of the feedin-priority standard mode. A variation for self-use mode can be created by replacing "Enabled Battery Control" by "Enabled Grid Control"

alias: Houseload from grid (and PV)
description: ""
trigger:
  - platform: time_pattern
    minutes: "0"
    seconds: "15"
condition:
  - condition: template
    value_template: >-
      {{states('sensor.ecopower_consumption_price') <
      states('input_number.no_discharge_price_threshold')}}
  - condition: template
    value_template: >-
      {{states('sensor.ecopower_consumption_price') >=
      states('input_number.charge_price_threshold')}}
  - condition: template
    value_template: >-
      {{states('sensor.solax_battery_capacity') | float(10.0) <
      states('input_number.target_soc') | float(0) + 3 }} 
action:
  - service: number.set_value
    data:
      value: "0"
    target:
      entity_id: number.solax_remotecontrol_active_power
  - service: select.select_option
    data:
      option: Enabled Battery Control
    target:
      entity_id: select.solax_remotecontrol_power_control
  - service: number.set_value
    data:
      value: "3600"
    target:
      entity_id: number.solax_remotecontrol_autorepeat_duration
  - service: button.press
    data: {}
    target:
      entity_id: button.solax_remotecontrol_trigger
mode: single

Solax Gen3 approach

To be documented

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