rctpower_writesupport

Write support for RCT Power Serial Protocol with rctclient

Important: For safety reasons, there should be no other connections to the inverter (RCT Power App, HA Integration, OpenWB, EVCC etc.)

Also important: This is an experimental tool and therefore not function nor dangerous conditions or damage to the controlled system can be excluded. All risk lies on the owner of the equipment!

Refer also to: rctclient | write support

Table of contents

1. Scenarios
2. Usage
3. Homeassistant Integration with pyscript
4. Home Assistant Integration as package
5. Links

Scenarios

Charging from the grid for e.g. Tibber

1. Set power_mng.soc_strategy to 2
2. Set power_mng.battery_power_external to the desired charging power (e.g. -6000 = 6 kW)
3. Wait until SOC target is reached
4. Set power_mng.soc_strategy to 4
5. Set power_mng.battery_power_extern to 0

Discharge lock during e-car charging

This also prevents excess charging. The battery is therefore not used at all.

1. Set power_mng.soc_strategy to 2
2. Set power_mng.battery_power_external to 0
3. Wait as long as the car is charging
4. Set power_mng.soc_strategy to 4

Emergency power reserve

To adjust the available emergency power reserve for the dark season, the value power_mng.soc_min can be increased. You should then also increase power_mng.soc_charge in order to recharge from the grid to maintain power_mng.soc_min.

Increase:

1. Set power_mng.soc_min to 0.30 (for 30%)
2. Set power_mng.soc_charge to 0.28 (for 28%)

Set to default:

1. Set power_mng.soc_min to 0.07 (for 7%)
2. Set power_mng.soc_charge to 0.05 (for 5%)

Usage

rct.py get <parameter> --host=<ip_address_or_hostname>
rct.py set <parameter> <value> --host=<ip_address_or_hostname>

Valid Parameters:
  power_mng.soc_strategy - SOC charging strategy
    Valid Values:
      0: SOC target = SOC (State of Charge)
      1: Konstant (Constant)
      2: Extern (External)
      3: Mittlere Batteriespannung (Average Battery Voltage)
      4: Intern (Internal)
      5: Zeitplan (Schedule)
    Default Value: 4 (Internal)
  power_mng.soc_target_set - Force SOC target
    Valid Range: 0.00 to 1.00, with at most two decimal places
    Default Value: 0.50
  power_mng.battery_power_extern - Battery target power
    Valid Range: -6000 to 6000
      Positive values indicate discharge, negative values indicate charge
    Default Value: 0
  power_mng.soc_min - Min SOC target
    Valid Range: 0.00 to 1.00, with at most two decimal places
    Default Value: 0.07
  power_mng.soc_max - Max SOC target
    Valid Range: 0.00 to 1.00, with at most two decimal places
    Default Value: 0.97
  power_mng.soc_charge_power - Charging power to reach SOC target
    Default Value: 100
  power_mng.soc_charge - Trigger for charging to SOC_min
    Default Value: 0.05
  p_rec_lim[1] - Max. battery to grid power
    Valid Range: 0 to 6000
    Default Value: 0

Homeassistant Integration with pyscript

This is an elementary example, how the script could be used within Homeassistant.

Preperations

1. Install pyscript according to the installation instructions from this documentation.
   Afterwards, the integration is available: Within the the integration settings, make sure that all imports of all packackes is allowed: Hint: The internal integration "Python Scripts" of Home Assistant is not sufficient, because it is not possible to use Python imports with this integration. Refer to: Home Assistant | Integrations | Python Scripts.
   
   The integration should be ready for use, if basics Pyscript services are provided like this:

Implementation as Service

First, set up the follwing folders in the config folder of Home Assistant and copy the files "rct.py" and "rct_ha_call.py" from this repository to the folders:

Home Assistant Root Folder:
└── config
    └── pyscript
        ├── modules
        │   └── rct.py
        └── rct_ha_call.py

within the file rct_ha_call.py update the default arguments according to your needs:

@service
def rct_ha_call(action='set', parameter='power_mng.soc_max', value=0.97, host='192.168.0.99'):
    #"""Using rct.py to set/get parameter of the RCT inverter"""

    from rct import get_value, set_value

    output = set_value(parameter=parameter, value=value, host=host)
    print(output)
    log.info(f"rct_ha_call: {output}")

If a default value is provided, less arguments are needed when the service is called from Home Assistant as a service later. In this case, I just want to use to set the parameter of power_mng.soc_max of fixed inverter with IP 192.168.0.99.

Testing

Now, the service "rct_ha_call" should be available and the value: 0.97 is the data supplied to the service as the maximum state of charge:

Usage

Just my implementation for usage as an example:

1. input_number.rtc_soc_maximum is used to provide max. SOC
2. automation is calling the service, when the input number changes:

alias: Batterie RCT setze SOC Maximum
description: Setzt den den maximalen Speicherwert der Batterie über ein Python-Skript
trigger:
  - platform: state
    entity_id:
      - input_number.rtc_soc_maximum
    for:
      hours: 0
      minutes: 0
      seconds: 3
condition: []
action:
  - service: pyscript.rct_ha_call
    data:
      value: "{{states('input_number.rtc_soc_maximum')|multiply(0.01)|round(2)}}"
mode: single

Hint: Do not forget to scale the input number from percentage (i.e. 97%) to fractions (i.e. 0.97) by using the pipeline |multiply(0.01)|round(2), as the script expects values from 0...1 as input.

Home Assistant Integration as package

Home Assistant Root Folder:
└── config
    ├── packages
    │   └── rctpower.yaml
    └── rct.py

1. Copy rct.py to /config/rct.py
2. Copy packages/rctpower.yaml to /config/packages/rctpower.yaml
3. Edit /config/packages/rctpower.yaml and set the charging power for QuickCharge. Be careful!
4. Edit /config/packages/rctpower.yaml and change the IP to your inverter IP
5. Install Home Assistant RCT Power Integration
6. Restart HA

Links

Rctclient's documentation

Special RCT Infos

Starting on Page 32

HF-A21-SMT, Chapter 1.4.3

Pyscript: Python Scripting for Home Assistant | Documentation