High voltage hybrid inverter (GW6000-EH) with EV battery (Chevy Volt)

[powertrack]

Have here a protocol from a BYD HVM 22,1kWh batterie, connected on a Fronius Symo Gen24 10kW
Goodwe is able to handle (after an firmware update) a BYD HVM.
Data read with BYD BeConnect Plus

 

[prepared1]

Yasko: Glad to hear that it is working out. We happen to have a very large, regional company here that recycles all sorts of industrial storage systems, so it is an easy task to pick up a super heavy duty rack, cabinet, or what-ever, and for a good price. You just need patience, and then jump at the chance when you get it.

Keep at it!

 

[yasko]

@powertrack
The inverter came with its own Modbus power meter and all accessories needed for installation. That is a standard option from Goodwe, and I ordered by this way. When the inverter works in "General mode", it tries to maximize a self-consumption and keep zero feed-in.


The inverter also has an RS-485 (MODBUS RTU ) interface, and it's possible to implement complex control scenarios beyond the scope of the included app. I've found useful information here. This source code is a part of the openems.io project.

Thanks for the attached log from the BYD battery. I've checked my inverter version, and it supports the BYD HVM battery. But my communication interface is CAN-bus based, and Fronius uses MODBUS interface, so there is a big difference. I will check the data and see how to interpret them.

 

[Simon2021]

Have here a protocol from a BYD HVM 22,1kWh batterie, connected on a Fronius Symo Gen24 10kW
Goodwe is able to handle (after an firmware update) a BYD HVM.
Data read with BYD BeConnect Plus

Do you know how to read the values? So what they mean? I guess the maximum voltage, SOC, maximum current is transferred here, probably encoded by IEEE754 Single precision 32-bit or 64 bit

 

[yasko]

I've checked the data in the attached file, and it looks like a log file for debugging purposes. Real-time communication between the battery and the inverter can be quite different. The inverter datasheet states that it's MODBUS-based. If we have the actual log from the RS-485 bus, we can compare the data with the protocol between the Kostal inverter and the BYD battery.

 

[huntworker]

I've checked the data in the attached file, and it looks like a log file for debugging purposes. Real-time communication between the battery and the inverter can be quite different. The inverter datasheet states that it's MODBUS-based. If we have the actual log from the RS-485 bus, we can compare the data with the protocol between the Kostal inverter and the BYD battery.

would be very interesting to compare the data because in the setup of the old BYD B-Box HV (previous version of HVS or HVM) you need to set up your inverter brand. Not sure if this is relevant for the communication or just the interest of BYD.

 

[yasko]

In this post, I will briefly describe a software part of my project. I've created a repository on GitHub, and the current version of the software is here.
To run the software on Raspberry Pi, we need some preparation steps:

• After installing the CAN-BUS FD HAT, we have to permanently set the bit rate for the two interfaces (can0, can1). This is done by adding the following lines to /etc/network/interfaces.

• auto can0  iface can0 inet manual
  pre-up /sbin/ip link set can0 type can bitrate 125000
  up /sbin/ifconfig can0 up
  down /sbin/ifconfig can0 down
  
  auto can1
  iface can1 inet manual
  pre-up /sbin/ip link set can1 type can bitrate 250000
  up /sbin/ifconfig can1 up
  down /sbin/ifconfig can1 down

• Communication with battery is done on can0 interface at 125kbps bit rate, and inverter is on can1 at 250kbps.
• I'm running the software as a system service, and it's called bmsd. We need to copy the file bmsd.service to the folder /etc/systemd/system.

• Start service:
  sudo systemctl start bmsd
  Start service on boot:
  sudo systemctl enable bmsd

The current state of software is WIP, and I'm gradually upgrading it. I will add some descriptions of the supported function later.

 

[CarelHassink]

Yasen, can you tell me if the Goodwe is limited to 250kbps on the can bus, or can one set it to 500Kbps as well??
many thanks, best Carel

 

[yasko]

Carel, I think that the bitrate is somehow predefined. It depends on the battery chosen. For example, BYD batteries work at 500Kbps, but the default battery works at 250Kbps. I'm not sure whether this can be changed.

 

[CarelHassink]

Yasen thanks,
just wondered if it was just a tick in the software

 

[SeByDocKy]

Officially Goodwe doesn't support the usage of lead-acid batteries with the EH inverter series. But unofficially, I can confirm that GW6000-EH can work batteries without BMS with some limitations.
I'm attaching some screenshots from the "PV Master" app. When you choose a battery type, there is an option for a self-define model. Then it comes to a warning about usage of a lead-acid battery, and after that, you can choose battery parameters. The last screenshot shows the inverter using it in a self-define mode.

View attachment 23709 View attachment 23710View attachment 23712View attachment 23713

What are the limitations of self-define mode? The first issue: a SOC estimation doesn't match well for a Li-Ion battery and usually shows a higher value. Maybe LiFePO4 will work better. The second: max charging current is internally limited to 5.5A despite what you enter by the app.
There is SOC protection during discharge, but you can't set a min discharge voltage for the battery. Also, there is no temperature sensing in self-define mode.
I've been using my inverter in that mode for some time together with a Chevy Volt battery, but I think it's not suitable for Li-Ion batteries. I highly recommend BMS usage, and here is a screenshot of when there is a working BMS.

View attachment 23715

Hi,

Fantastic thread....... and got a plenty of questions. I am planning to buy the GW6000-EH and hope to build a DIY HV battery LifePO4 based.

i) Are you happy with the GW6000-EH : ? especially in grey sky conditions with the MPPT starting about 100V ? how to compare with some other chinese hybrid inverters ?

ii) what is it self consumption ? in ongrid and offgrid configurations ?

iii) Ok i understand from your post, actually define the DIY battery via the appz only, limits considerably its usage. Do you thing (for the 5.5A charge at least), it's a bug/limitation in the software ?

iv) Do you think will be possible to connect a open BMS with the GW6000-EH for a 2x48V LifePO4 battery ?


Thanks in advance for your answers.

 

[yasko]

Hi @SeByDocKy and welcome to the forum.
A DIY HV LiFePO4 battery sounds interesting, but be aware of HV DC voltage. Now about your questions:

1. Yes, I'm happy with GW6000-EH, and I think it works well at low light. I've seen as low as 20W PV power. It isn't easy to compare with other Chinese brands because I don't have previous experience. In my opinion, Goodwe has done a pretty good job.
2. Good question, but I still haven't measured the self-consumption of the inverter.
3. I think that a 5.5A charge current is a software limitation. But as I state before: I recommend a BMS communication with a default battery profile.
4. I think it's possible. By "open BMS," you mean this project or something else? At 96V, you will be limited to 2400-2500W discharge power from the battery.

I also have plans to migrate to LiFePO4 at some moment in the future because of safety. I even started designing my own BMS solution and can share some thoughts if you are interested.

 

[SeByDocKy]

Hi @SeByDocKy and welcome to the forum.
A DIY HV LiFePO4 battery sounds interesting, but be aware of HV DC voltage. Now about your questions:

1. Yes, I'm happy with GW6000-EH, and I think it works well at low light. I've seen as low as 20W PV power. It isn't easy to compare with other Chinese brands because I don't have previous experience. In my opinion, Goodwe has done a pretty good job.
2. Good question, but I still haven't measured the self-consumption of the inverter.
3. I think that a 5.5A charge current is a software limitation. But as I state before: I recommend a BMS communication with a default battery profile.
4. I think it's possible. By "open BMS," you mean this project or something else? At 96V, you will be limited to 2400-2500W discharge power from the battery.

I also have plans to migrate to LiFePO4 at some moment in the future because of safety. I even started designing my own BMS solution and can share some thoughts if you are interested.

Thanks for you answers @yasko, it helps me a lot in my choice. I am hesitating between this Goodwe (and go directly for a HV battery) or the Sarmentec 5KVa and stay in 48V (more or less the same than the GoodWe LV model but a bit cheaper).
What I like the most in this GoodWe is the fact tthat MPPT starts around 30V lower than other chinese brands. I will have two strings with 5 (maybe 6) and 8 panels respectively.... I will optimize all my setup for winter conditions (I am located in south of France).
So yes definitively, if I go for the GoodWe EH (now most probably), if you design a dedicaced BMS which can be easily integrated with, I will be one of your follower. Ho another question, did you wire your goodwe in Offgrid or gridtie configuration ? Maybe there is a discord associated with this forum where we can communicate more easily ?

Thanks a lot.

 

[yasko]

I'm using the inverter in on-grid mode but without exporting energy to the grid. It's possible to set zero limits export value.
I hope tomorrow will have some more time and write more about the inverter and planed BMS.

 

[SeByDocKy]

I'm using the inverter in on-grid mode but without exporting energy to the grid. It's possible to set zero limits export value.
I hope tomorrow will have some more time and write more about the inverter and planed BMS.

Great ... Définitively I need some feedbacks about this inverter... In Youtube, 0 vidéo available.

 

[yasko]

OK, a few words about the inverter and its work. It has four main modes of operation:


I'm using it in general mode, with zero export to the grid. The generated PV energy is used for self-consumption, and I suspect this is not the optimal usage. I can't consume all energy produced by PV panels and usually end up with a fully charged battery on sunny days now.
An example of energy flow:


Usually, during the day, when the inverter charges the battery, there is a small consumption from the grid despite the energy produced by PV panels and house consumption.
An energy production on a sunny day (taken from Goodwe energy portal):


This is how the inverter typically works. I'm not sure how good it is compared to other brands, but I have no complaints, and the systems work well. I have some plans for an energy control and monitoring system using the inverter's MODBUS port, but thill will take some time.
@SeByDocKy, If you have some specific questions regarding the inverter, let me know. I understand the fact that these machines are quite new and there is little information available.

 

[SeByDocKy]

OK, a few words about the inverter and its work. It has four main modes of operation:

View attachment 24254 View attachment 24255
I'm using it in general mode, with zero export to the grid. The generated PV energy is used for self-consumption, and I suspect this is not the optimal usage. I can't consume all energy produced by PV panels and usually end up with a fully charged battery on sunny days now.
An example of energy flow:
View attachment 24256

Usually, during the day, when the inverter charges the battery, there is a small consumption from the grid despite the energy produced by PV panels and house consumption.
An energy production on a sunny day (taken from Goodwe energy portal):

View attachment 24258
This is how the inverter typically works. I'm not sure how good it is compared to other brands, but I have no complaints, and the systems work well. I have some plans for an energy control and monitoring system using the inverter's MODBUS port, but thill will take some time.
@SeByDocKy, If you have some specific questions regarding the inverter, let me know. I understand the fact that these machines are quite new and there is little information available.

Thanks for these feedbacks

1) You mentioned that time to time there are some consumptions from grid, do you have an estimate for a typical day ? More in day vs night ? I guess it's more or less the self-consumption in ongrid mode ?
What about injection despite setting this value to 0W, do you measure some little injections, if yes do you have a raw estimate ?

2) How noisy is the inverter ? (I plan to install it in a room inside my house, not in a garage)

3) With some friends, for Offgrid configuration we developped a solar router to improve general performances to send extra potential energy into a pure resistive load (a water tank for example) whille charging the battery : https://github.com/bidouilleurs/routeur_solaire
This is why, if I choose the goodwe, I will use more probably the offgrid setup but it will be possible only if the communication between a DIY BMS and the goodwe is efficient

4) Where you bought your GW6000-EH and how much ?

Thanks for your your time spent to answer to my newbaby questions.

 

[yasko]

@SeByDocKy, a brief comments to your questions:

1) This consumption varies around 100-300W, which gives around 2-3kWh/day. During the nights, I noticed if increase load to the inverter (500 - 1000W), the grid consumption goes to almost zero. Bur during the days when charging the battery, there is a grid consumption. Here is an example form today with almost full power from PV array:

It's interesting that if I disconnect the battery, then the inverter reduces the grid consumption to zero.
There is some injection to the grid, but it's negligible, below one percent of the total produced amount.
2) It's a fanless inverter, and it's very quiet indeed.
3) This is an interesting project, and I will check it. Maybe I need such a device for the hot summer days. Some time ago, I found a similar device - Fronius Ohmpilot, but I think it works only with a Fronius inverter.
4. I've ordered my inverter from a German distributor. It costs me around 1400 euros, including shipping and VAT. I will send you the details on PM.

 

[SeByDocKy]

@SeByDocKy, a brief comments to your questions:

1) This consumption varies around 100-300W, which gives around 2-3kWh/day. During the nights, I noticed if increase load to the inverter (500 - 1000W), the grid consumption goes to almost zero. Bur during the days when charging the battery, there is a grid consumption. Here is an example form today with almost full power from PV array:
View attachment 24268
It's interesting that if I disconnect the battery, then the inverter reduces the grid consumption to zero.
There is some injection to the grid, but it's negligible, below one percent of the total produced amount.
2) It's a fanless inverter, and it's very quiet indeed.
3) This is an interesting project, and I will check it. Maybe I need such a device for the hot summer days. Some time ago, I found a similar device - Fronius Ohmpilot, but I think it works only with a Fronius inverter.
4. I've ordered my inverter from a German distributor. It costs me around 1400 euros, including shipping and VAT. I will send you the details on PM.

Hi,

Hummmm point 1) is scarrying me.... I don't know why the goodwe has a so important grid consumption.... I would accept for few watts (< 5w)... it means the feedback regulation via the energy meter is not done correctly....., even it these 100-300W are only in peaks.... a fraction of second.
Did you contact GoodWe for this ? coz according to your graph, it's clear that the goodwe send to much ampere into the battery regarding the PV production. A firmware should fix that....

3) Yes the new fronius gen24+ can be completed with a solar router .... but actually the Primo Gen 24+ is still not available

4) Thanks a lot ... I will reply in PM

 

[bikefish]

Hi,
Interesting discussion.
I'm also interested in information on the efficiency of the GoodWe. How is the self consumption?
I'm planning something similar, but I'm still sourcing the battery cells.