Python library for connecting to Huawei SUN2000 Inverters over Modbus

This library implements an easy to use interface to locally connect to Huawei SUN2000 inverters over Modbus-TCP or Modbus-RTU following the 'Solar Inverter Modbus Interface Definitions' provided by Huawei.

It was primarily developed to add support for Huawei Solar inverters to Home Assistant, resulting in the following integration: wlcrs/huawei_solar.

Features:

• Modbus-TCP support: connecting to the inverter via the SDongle, or over the WiFi-AP (SUN2000-<serial_no>) broadcasted by the inverter
• Modbus-RTU support: connecting to the inverter via the RS485A1 and RS485B1 pins on the COM port
• Batched reading of Modbus registers and converting them into the correct units
• Reading Optimizer data via the specialized 'file' Modbus extension
• Writing to Modbus registers (mostly useful for setting battery parameters)
• Performing the login sequence to gain 'installer'-level access rights

Note t

Installation

This library is published on PyPI:

pip3 install huawei-solar

Basic usage

The library consists out of a low level interface implemented in huwei_solar.py which implements all the Modbus-operations, and a high level interface in bridge.py which facilitates easy usage (primarily meant for the HA integration).

Using the high level interface

An example on how to read the most interesting registers from the inverter:

bridge = await HuaweiSolarBridge.create(host="192.168.200.1", port=6607)
print(await bridge.update())

This results in the following output being printed:

{'input_power': Result(value=82, unit='W'), 'line_voltage_A_B': Result(value=233.4, unit='V'), 'line_voltage_B_C': Result(value=0.0, unit='V'), 'line_voltage_C_A': Result(value=0.0, unit='V'), 'phase_A_voltage': Result(value=247.2, unit='V'), 'phase_B_voltage': Result(value=0.3, unit='V'), 'phase_C_voltage': Result(value=0.0, unit='V'), 'phase_A_current': Result(value=0.408, unit='A'), 'phase_B_current': Result(value=0.0, unit='A'), 'phase_C_current': Result(value=0.0, unit='A'), 'day_active_power_peak': Result(value=2407, unit='W'), 'active_power': Result(value=70, unit='W'), 'reactive_power': Result(value=-1, unit='VA'), 'power_factor': Result(value=1.0, unit=None), 'grid_frequency': Result(value=50.02, unit='Hz'), 'efficiency': Result(value=100.0, unit='%'), 'internal_temperature': Result(value=24.4, unit='°C'), 'insulation_resistance': Result(value=30.0, unit='MOhm'), 'device_status': Result(value='On-grid', unit=None), 'fault_code': Result(value=0, unit=None), 'startup_time': Result(value=datetime.datetime(2022, 11, 18, 9, 2, 40, tzinfo=datetime.timezone.utc), unit=None), 'shutdown_time': Result(value=None, unit=None), 'accumulated_yield_energy': Result(value=3515.62, unit='kWh'), 'daily_yield_energy': Result(value=0.12, unit='kWh'), 'state_1': Result(value=['Grid-Connected', 'Grid-Connected normally'], unit=None), 'state_2': Result(value=['Locked', 'PV connected', 'DSP data collection'], unit=None), 'state_3': Result(value=['On-grid', 'Off-grid switch disabled'], unit=None), 'alarm_1': Result(value=[], unit=None), 'alarm_2': Result(value=[], unit=None), 'alarm_3': Result(value=[], unit=None), 'pv_01_voltage': Result(value=287.8, unit='V'), 'pv_01_current': Result(value=0.0, unit='A'), 'pv_02_voltage': Result(value=0.0, unit='V'), 'pv_02_current': Result(value=0.0, unit='A'), 'nb_online_optimizers': Result(value=10, unit=None), 'grid_A_voltage': Result(value=234.1, unit='V'), 'grid_B_voltage': Result(value=234.1, unit='V'), 'grid_C_voltage': Result(value=233.1, unit='V'), 'active_grid_A_current': Result(value=-0.48, unit='I'), 'active_grid_B_current': Result(value=-0.46, unit='I'), 'active_grid_C_current': Result(value=-0.56, unit='I'), 'power_meter_active_power': Result(value=-151, unit='W'), 'power_meter_reactive_power': Result(value=187, unit='Var'), 'active_grid_power_factor': Result(value=-0.428, unit=None), 'active_grid_frequency': Result(value=50.0, unit='Hz'), 'grid_exported_energy': Result(value=1705.65, unit='kWh'), 'grid_accumulated_energy': Result(value=1048.0, unit='kWh'), 'grid_accumulated_reactive_power': Result(value=0.0, unit='kVarh'), 'meter_type': Result(value=<MeterType.THREE_PHASE: 1>, unit=None), 'active_grid_A_B_voltage': Result(value=405.3, unit='V'), 'active_grid_B_C_voltage': Result(value=404.6, unit='V'), 'active_grid_C_A_voltage': Result(value=404.6, unit='V'), 'active_grid_A_power': Result(value=-72, unit='W'), 'active_grid_B_power': Result(value=-71, unit='W'), 'active_grid_C_power': Result(value=-7, unit='W'), 'storage_state_of_capacity': Result(value=22.0, unit='%'), 'storage_running_status': Result(value=<StorageStatus.RUNNING: 2>, unit=None), 'storage_bus_voltage': Result(value=454.2, unit='V'), 'storage_bus_current': Result(value=0.0, unit='A'), 'storage_charge_discharge_power': Result(value=12, unit='W'), 'storage_total_charge': Result(value=1094.26, unit='kWh'), 'storage_total_discharge': Result(value=1049.3, unit='kWh'), 'storage_current_day_charge_capacity': Result(value=0.39, unit='kWh'), 'storage_current_day_discharge_capacity': Result(value=0.15, unit='kWh')}

Using the low level interface

Example code:

from huawei_solar import AsyncHuaweiSolar, register_names as rn

slave_id = 0
client = await AsyncHuaweiSolar.create("192.168.200.1", 6607, slave_id)

# Reading a single register

result = await bridge.client.get(rn.NB_PV_STRINGS, slave_id)
print("Number of PV strings: ", result.value)

# Batched reading of multiple registers
# Only possible when they are located closely to each other in the Modbus register space

results = await self.client.get_multiple([rn.LINE_VOLTAGE_A_B, rn.LINE_VOLTAGE_B_C, rn.LINE_VOLTAGE_C_A], self.slave_id)
print("A-B voltage: ", results[0].value)
print("B-C voltage: ", results[1].value)
print("C-A voltage: ", results[2].value)

A good starting point to learn how to use the low level interface is to look at how the high level interface in bridge.py uses it.

Acknowledgements

The initial implementation of v1 was done by @Emilv2.

Subsequent developement on v2 was done by @wlcrs.