Inverter: Sungrow - dalathegreat/Battery-Emulator GitHub Wiki

[!CAUTION] Working with high voltage is dangerous. Always follow local laws and regulations regarding high voltage work. If you are unsure about the rules in your country, consult a licensed electrician for more information. DC ARC is a REAL THING - ENSURE NO LOAD is on any DC wires before working on the system.

Compatible Sungrow Inverters

  • Sungrow SH5.0/6.0/8.0/10RT: ✅ (BYD_CAN)
  • Sungrow SH3.0/3.6/4.0/5.0/6.0RS: ✅ (BYD_CAN)
  • Sungrow SH3.0/3.6/4.0/5.0/6.0RS: Australia No BYD support, use SUNGROW_CAN instead
  • Sungrow SH8.0RS/SH10RS, SH15T-25T: Australia No BYD support, use SUNGROW_CAN instead
  • Sungrow SH15/20/25T: question: Unclear which protocol to use

Note: In some countried support for BYD is officially dropped, for instance in the new SH15T, SH20T and SH25T. Sungrow wants to promote their own battery system. In some countries it's rumored to even be dropped in the SHxRT models. If you have a model that cannot use BYD_CAN, try to use SUNGROW_CAN to emulate a Sungrow SBR064 battery instead. As of June 2024, Australia has officially dropped all support for batteries other than Sungrow: https://service.sungrowpower.com.au/TI_20210824_Approved%20battery%20declaration%20for%20sungrow%20hybrid%20inverters_V16_EN-1.pdf

SUNGROW_CAN is currently under testing, as at Dec 2024.

Communication wiring

The Sungrow inverter works via CAN. The LilyGo board can have both a CAN battery and a CAN inverter connected on the same pins. When the board is used with two CAN devices at the same time that have termination resistors in all ends, the terminating resistor needs to be removed from the board. Please measure CAN termination if you have issues. This is explained in CAN-troubleshooting

ℹī¸ Always check the termination resistance of the system! That way you know if resistor needs to be removed or not.

ℹī¸ Grounding is extremely important. Make sure the battery case is connected to protective earth, and the shield part of the twisted pair CAN is connected to PE also! Failing to do this will result in CAN errors.

If the inverter CAN wiring is correct and with the inverter on, you should see a voltage of over 1V (eg 1.38V) - wires plugged into the inverter only.

Some Sungrow inverters seem to have CAN communication issues when the battery and inverter are on the same LilyGo (known issue with SH5.0RS and Leaf battery). To resolve this, using two LilyGos to separate the inverter from the battery CAN is a good option. You can find a "how to" here (https://github.com/dalathegreat/BYD-Battery-Emulator-For-Gen24/wiki/Double-LilyGo#how-to-connect-it) Note: when using two LilyGos, both LilyGos need to have their terminating resistors present!

ℹī¸ If you are using only a single LilyGo board, Sungrow has a nasty software bug. Incase the LilyGo board is disconnected while the system is running (wire break or hardware failure), the inverter will still charge/discharge the battery! This is because the Sungrow inverter sees the automotive CAN messages as the system still being alive. This can lead to a dangerous situation where the battery is over/under-charged. This can be avoided by using a Dual-LilyGo setup!

Sungrow Inverters have the wiring diagram on the side of the Inverter, check this, some are different. As at 2024, the inverter wiring diagram for an 'SHxxRS' Inverter is:

image

Note: Sungrow inverters also have an inbuilt FUSE on the battery terminals. CHeck the data Spec sheet: SH3.0_3.6_4.0_5.0_6.0RS image

Compiling the software for Sungrow inverters

Make sure that the settings in the "USER_SETTINGS.h" file are correct. The line:

#define BYD_CAN //Enable this line to emulate a "BYD Battery-Box Premium HVS" over CAN Bus

Needs to be uncommented for the software to emulate the BYD protocol over CAN. Next step is then to select the battery that you intend to use, for instance if you use LEAF battery, make sure the following line is uncommented:

#define BATTERY_TYPE_LEAF // See NISSAN-LEAF-BATTERY.h for more LEAF battery settings

After setting this up, flash the board!

Setting up the Sungrow inverter for self-consumption mode2

ℹī¸ If you want to limit export power into the grid (feed-in) you will need to use Sungrow Smartmeter.

It is needed so that the system can measure consumption and generation.

Sungrow Smart Meter model "DTSU666" that comes with the SH10RT is compatible.

Adjust the parameters in Winet-S local web interface through web browser, iSolarCloud app or isolarcloud.com

Settings at Winet-S local web interface

Settings at isolarcloud.com

Note, it takes 10-15minutes for the icloud software to update the details for the Inverter.

Starting and stopping the system (Leaf specific)

When turning the system on, follow this startup procedure. Work quick, to avoid the inverter getting stuck in battery not detected mode.

Startup

  1. First start the Sungrow inverter via AC switch
  2. Turn on the Solar DC switch
  3. Turn on the Battery DC switch
  4. Start the LEAF battery BMS with 12V
  5. Start the LilyGo hardware with 5V
  6. Then either handle precharge/contactor closing manually or let the LilyGo hardware handle it automatically

Shutdown

  1. Turn off the LEAF BMS, cut the 12V supply to it. Wait 60seconds
  2. LilyGo status LED will turn red. The Sungrow inverter will within 30seconds stop using the battery.
  3. After 30s has passed, turn off the contactors incase the LilyGo isn't setup to automatically handle them
  4. Turn off the Sungrow inverter via AC switch
  5. Turn off the Battery DC switch
  6. Turn off the Solar DC switch