8851 inverter protocol integration ESPHome component

Denial of Responsibility

Disclaimer: Messing up with inverter parameters could lead to inverter or battery failure. Please make sure you understand what you are doing. This project is provided "as-is" without any warranty or support of any kind. By using this software, you agree that:

1. No Warranty: The project is provided without any warranty, expressed or implied. The entire risk of using the project is assumed by you, the user.
2. No Support: The author(s) of this project are under no obligation to provide support, updates, or maintenance. Issues and pull requests may be addressed at the sole discretion of the project contributors.
3. Use at Your Own Risk: The project may involve experimental features or third-party dependencies, and the user is responsible for ensuring its compatibility with their system. The author(s) are not responsible for any damage, data loss, or other consequences that may arise from the use of this project.
4. No Guarantee of Compatibility: The project may not be compatible with all environments, hardware, or software configurations. It is the user's responsibility to verify compatibility before use.
5. Security Considerations: The project may not have undergone a comprehensive security review. Users are advised to exercise caution and not use this project in critical or security-sensitive applications.
6. Third-Party Dependencies: This project may rely on third-party libraries, frameworks, or tools. The user is responsible for complying with the licenses and terms associated with these dependencies.

By using this project, you acknowledge and agree to these terms. If you do not agree with these terms, do not use or contribute to this project.

Compatible inverters

• PowMr POW-HVM6.5K-48V (tested by @lufton)
• PowMr POW-HVM4.5K-24V
• Simular inverters that utilize the same DTU (WBS1-V001)

Capabilities

This component will let you monitor (sensors, binary sensors and text sensors) and control (numbers and selects) compatible inverter without need of installing Chinese software and depend on any third-party services.

Why to use this component

• No need to use original software. Chinese mobile app doen't work stable, is slow and not reliable.
• No need to send you data to custom server. All data sent from DTU with original firmware are stored with open access MQTT server. That is potential security breach, that can lead to data leak and even your inverter configuration changes witch can damage you hardware.
• Some extra configuration parameters that are absent in the app, like output_frequency, warning_buzzer, inverter_maximum_power.
• Possiblity to set some configuration parameters more accurately, like battery_charge_cut_off_current, output_voltage, total_charge_current, util_charge_current. You can set tham as any number from the range in comparison to inverter's menu where you can only select values from predefined options.
• Simple integration with 3rd party services like Home Assistant.
• Local automations.

Minimal configuration

uart:
  - baud_rate: 9600

inv_8851:
  version: 1 # read about this parameter below

sensor:
  - platform: inv_8851
    battery_voltage:
      name: "Battery voltage"
    ...

Full list of available entities is here.

Options

There are several options you may need to set:

• update_interval
• version

update_interval tells how often to request state and configuration from inverter, default value is 5s and should suite most situations.

inv_8851:
  update_interval: 30s

version should be one of 1 (confirmed firmware version: 0005) or 2 (confirmed firmware version: 8100). Right now there are several protocol versions. They are pretty similar except they have a bit different packets length. 144/90 bytes for version=1 and 148/94 bytes for version=2 (state and config data block length respectively). If you experience problems with changing parameters it could mean that you should try other value (you can use substitutions→version parameter). It's only my guess, but it looks like version 1 is not compatible with newer firmware, so try using version 2 for newer models. Also you should see warning messages in logs if you peaked wrong version.

24v vs 48v version

24v and 48v files are different only in configuration of some entities witch has no sense for 24v version (bms_cell_09_voltage — bms_cell_16_voltage) and minimum/maximum values for some number entities (as they depend on voltage). So in theory flashing "wrong" configuration shouldn't make any harm to ESP or inverter.

...-local.yaml

This project build to be as simple is possible, so in most cases you woudn't need those files. Regular .yaml file will download latest stable version from this repository and use it upon build process. But if you want to customize configuration or you plan to change files in packages or components directories, than you probably want to use those. Also -local.yaml files include debugging by default.

inverter_maximum_power

First of all there are two places you can find inverter_maximum_power parameter:

• Under substitutions section of example files
• Under number configuration section

The reason for that parameter present in substitutions section is to limit max_value parameter for inverter_maximum_power number entity. This is needed to prevent user from setting to high value for that entity.

Number entity inverter_maximum_power sets software limitaion for inverter's maximum power (total power inverter consumes from grid including battery charging power). Setting value that is higher than factory-default (4500W for 4.5kW inverter version and 6500W for 6.5kW inverter version) for that number entity can lead to potential damage. From other hand you can set software limitaion lower than factory-default to protect your inverter from working in conditions close to maximum possible and prolong it's life. In case of exceeding 110% of inverter_maximum_power value, inverter will turn off with error code of 07.

Please make sure you understand what you're doing before adjusting this parameter.

Flashing DTU WBS1-V001

You can flash WBS1-V001 using this component (use corresponding dtu-wbs1-v001...-example.yaml file). This way you can use original DTU with much more comfortable and easy way. This configuration also supports onboard LED indication. In order to flash original DTU follow next steps:

1. Disassemble DTU (it has 4 screws in the corners under the foamy sticker on the bottom)
2. Solder pin headers of jump wires to +5V, GND1, BOOT1, RXD1, TXD1 pads (they are labeled)
3. Connect USB to TTL module VCC → +5V, RX → TXD1, TX → RXD1 and GND → GND1 with BOOT1 pin connected to GND1
4. Dump and store original firmware using esptool (replace COM1 with valid port number):
   esptool.exe -p COM1 -b 460800 read_flash 0x0 0x400000 DTU.bin
5. Flash ESPHome with corresponding configuration
6. Disconnect USB to TTL module, assemble DTU and connect to inverter
7. In order to restore original firmware connect DTU and USB to TTL module with BOOT1 pin connected to GND1 and run command (replace COM1 and DTU.bin with valid port number and firmware dump file backed up in step 4 path):
   esptool.exe -p COM1 -b 460800 write_flash 0x0 DTU.bin

Flashing ESP32 or ESP8266

You can flash ESP32 or ESP8266 using this component the same way you flash your other ESPHome projects. Read official guides if you have any questions.

Debugging

If you have data retrival issues consider enabling debugging. In order to do so:

1. Clone this repo locally git clone https://github.com/lufton/esphome-inv-8851.git
2. Change secrets.yaml file accordingly
3. Flash your device with ...-local.yaml file that matches your hardware
4. Check sireal port output, you should see:
   • Packets sent (>>> 88 51 ...) to inverter (should be present in any case)
   • Packets received (<<< 88 51 ...) from inverter (could be missing if there is an issue with communication between inverter and ESP8266/ESP32)
5. Packets should start with 88 51 ... (that's why this project and protocol was called 8851):
   • If you see incoming packets witch starts with 88 51 ..., then it means your connection is correct, even though if you don't receive any values from inverter. That could mean you have other protocol revision witch could be analized and implemented. In this case just create an issue with your findings.
   • If you see incoming packets witch starts with somesing else, then it means you definetly have an issue with wiring and noise. Check connection once again and try to use shorter wires.
   • If you don't see any incoming packets, then it could mean that there is something wrong with wiring or hardware. Check connection once again and make sure hardware you use is working corectly.

Available entities

Sensors

ID	Description	Unit	Res.
battery_charge_current	Maximum current to charge battery. It will start decreasing when battery enter absorption stage.	A	0.1
battery_voltage		V	0.01
bms_battery_current		A	0.1
bms_battery_soc		%	1
bms_battery_voltage		V	0.01
bms_cell_01_voltage		V	0.01
bms_cell_02_voltage		V	0.01
bms_cell_03_voltage		V	0.01
bms_cell_04_voltage		V	0.01
bms_cell_05_voltage		V	0.01
bms_cell_06_voltage		V	0.01
bms_cell_07_voltage		V	0.01
bms_cell_08_voltage		V	0.01
bms_cell_09_voltage		V	0.01
bms_cell_10_voltage		V	0.01
bms_cell_11_voltage		V	0.01
bms_cell_12_voltage		V	0.01
bms_cell_13_voltage		V	0.01
bms_cell_14_voltage		V	0.01
bms_cell_15_voltage		V	0.01
bms_cell_16_voltage		V	0.01
bts_temperature		°C	1
bus_voltage		V	0.1
fan1_speed_percentage		%	1
fan2_speed_percentage		%	1
grid_current		A	0.01
grid_frequency		Hz	0.01
grid_voltage		V	0.1
inverter_apparent_power		VA	1
inverter_apparent_power_percentage		%	1
inverter_current		A	0.01
inverter_frequency		Hz	0.01
inverter_power_percentage		%	1
inverter_software_version		N/A	1
inverter_voltage		V	0.1
inverter_voltage_dc_component		?	?
load_apparent_power		VA	1
load_current		A	0.01
load_power		W	1
log_number		N/A	1
low_load_current		A	0.01
ntc2_temperature		°C	1
ntc3_temperature		°C	1
ntc4_temperature		°C	1
parallel_current		A	0.01
parallel_frequency		Hz	0.01
parallel_voltage		V	0.1
pv_current		A	0.01
pv_power		W	1
pv_voltage		V	0.1

Binary sensors

ID	Description
battery	Indicates if battery is connected
buck_topology_initialization	Indicates if buck topology is initialized
bus	?
bus_and_grid_voltage_match	?
charging	Indicates if battery is still charging
disable_utility	? Indicates if inverter works in bypass mode
equalization_finished	Indicates if battery equalization program is finished
equalization_started	Indicates if battery equalization program is started
float_charging	Indeicates if battery is in float charging mode
grid_pll	Indicates if inverter phase is locked
inverter_topology_initialization	Indicates if inverter's topology is initialized
llc_topology_initialization	Indicates if LLC topology is initialized
parallel_lock_phase	Indicates if phases of inverters connected in parallel are locked
pv_excess	Indicates if there is PV power excess avaiable
pv_input	Indicates if PV is connected
pv_topology_initialization	Indicates if PV topology is initialized
system_initialization	Indicates if all inverter's systems are initialized
system_power	Indicates if inverter is turned on using button on left side

Text sensors

ID	Description
buck_topology	Buck topology state
inverter_topology	Inverter topology state
llc_topology	LLC topology state
pv_topology	PV topology state

Selects

ID	Description	Options	Menu
auto_return	Auto return to home screen after 1 minute of inactivity	OFF ON	19
backlight	Backlight always ON mode	OFF ON	20
battery_equalization	Battery equalization program activation	OFF ON	33
battery_type	Battery type selection. If User-defined type is selected, then additional voltage parameters can be set.	AGM Flooded User-defined Library	05
buzzer	Buzzer that beep every time you press any screen button	OFF ON	18
charge_energy_priority	Charger source priority	PV & Grid — PV and Grid at the same time PV > Grid — Priority for PV, then Grid PV only — Only PV	16
fault_record	Record fault code	OFF ON	25
frequency	Default frequency output mode, can be adjusted with output_frequency number	50Hz 60Hz	09
grid_voltage_range	Grid voltage range in witch inverter will work, otherwise will switch to battery	APL — 90-265V UPS — 170-265V	03
on_grid	Send produced enery to Grid	OFF ON	10
output_energy_priority	Which source to use first: Grid or PV	PV > Grid > Battery — Grid over battery PV > Battery > Grid — Battery over grid	01
overload_restart	Automatic restart after overload protection	OFF ON	06
overtemp_restart	Automatic restart after over temperature protection	OFF ON	07
parallel_operation	Parallel operation mode	OFF ON	14
phase	Witch phase inverter is connected to	A B C	15
power_buzzer	Buzzer that beep every time Grid becomes unavailable	OFF ON	22
powersave_mode	Power save mode, will pulse output voltage to determine and start if load is connected	OFF ON	04
warning_buzzer	Buzzer that beep every time inverter raise warning	OFF ON	N/A

Numbers

ID	Description	Unit	Res.	Range	Menu
battery_back_to_util_voltage	Voltage point at witch inverter will switch to Grid in PV > Battery > Grid mode	V	0.1	20…29.2 40…58.4	13
battery_bulk_voltage	Fully charged battery voltage	V	0.1	24…29.2 48…58.4	26
battery_float_voltage	Floating charging mode voltage	V	0.1	24…29.2 48…58.4	27
battery_charge_cut_off_current	Charge current at witch inverted assumes that battery is fully charged and switches into floating charging mode	A	0.1	2…20	12
battery_cut_off_voltage	Minimum battery voltage, inverter will disconnect battery at this point	V	0.1	20…24 40…48	29
battery_equalization_interval	How often battery equalization program will be triggered	Day	1	0…90	37
battery_equalization_time	How long battery equalization program will run	Min.	1	5…900	35
battery_equalization_timeout	How long battery equalization program can run before terminating	Min.	1	5…900	36
battery_equalization_voltage	Battery equalization voltage	V	0.1	25…29.5 50…59	34
inverter_maximum_power	Inverter maximum output power	W	1	0…4500 0…6500	N/A
output_frequency	Output frequency, that can be in range 50-55Hz for 50Hz mode and 60-55Hz for 60Hz mode	Hz	1	50…55 60…55	N/A
output_voltage	Output voltage, resets to closest lower number that is multiple of 5 (234V → 230V, 229V → 225V) after exiting menu	V	1	100…240	08
total_charge_current	Maximum battery charge current equals PV current + Grid current	A	0.1	0…130 0…150	02
util_charge_current	Maximum current used from Grid to charge battery	A	0.1	0…110 0…140	11

WBS1-V001 simplified schematics

WBS1-V001 module pictures

Original firmware dump

Here you can find original firmware dump file. Restore procedure described in the last step of Flashing DTU WBS1-V001 section.

Thanks

• @leodesigner for his work on powmr4500_comm
• @aquaforum for his work on c++ header file and protocol reverse engineering