Schneider XW Pro 6848 Charging/Discharging Power and Power Input/Output Modbus Map Questions

[Eric_Li]

Hello everyone, I would like to use Modbus to control the XW Pro 6848 to output or input the power values I calculate. However, I couldn't find corresponding registers on the Modbus Map to input the calculated charging or discharging power. I'm using Modbus Map version 990-91343CAug 10, 2021.

Equipment list:

• Schneider XW Pro 6848
• Schneider MPPT 60 100
• Schneider InsightHome
• 2.4KW battery

 

[BentleyJ]

This is a duplicate post

 

[Eric_Li]

This is a duplicate post

Do you have a link to the relevant post? I haven't seen it yet or I missed it, thank you

 

[BentleyJ]

Your original post received 2 responses, now I can't find it. Maybe the administrator deleted the wrong one.

I mentioned that the document number you posted for the modbus map didn't look familiar as the ones we have start with 503-*. I also noted that most of the data registers are Read only so you couldn't inject calculated values anyway even if you know the modbus address. Its only the user set menu items that take user inputs that are rw.

Then another member attached this for you.

 

[Eric_Li]

Your original post received 2 responses, now I can't find it. Maybe the administrator deleted the wrong one.

I mentioned that the document number you posted for the modbus map didn't look familiar as the ones we have start with 503-*. I also noted that most of the data registers are Read only so you couldn't inject calculated values anyway even if you know the modbus address. Its only the user set menu items that take user inputs that are rw.

Then another member attached this for you.

This is the bad news... I have a project that needs to use Python to develop a program to control the input and output power, because I want to smooth solar energy. Is there any other way to solve it?

 

[BentleyJ]

A WattNode can be attached to regulate sell back power by changing the Sell Amps value. Please describe exactly what you are trying to accomplish. There are others on the forum with excellent knowledge of how to integrate a PLC or Node Red into your system.

 

[BentleyJ]

GXMnow has posted quite a bit of information regarding integration of a Nano-10 PLC and there are a couple of recent threads related to using Node Red with modbus. What exactly are you trying to do with input and output power?

 

[Eric_Li]

GXMnow has posted quite a bit of information regarding integration of a Nano-10 PLC and there are a couple of recent threads related to using Node Red with modbus. What exactly are you trying to do with input and output power?

I want to use the charging and discharging of the battery to compensate for solar energy and control its rate of change. When the solar power generation is too high, the battery absorbs it, and when it is too low, the battery outputs to smooth the solar energy.

 

[BentleyJ]

The MPPT 60 100 already does that. You can use the modbus interface to change the user settings on the charge controller if that is what you are looking for.

 

[Eric_Li]

The MPPT 60 100 already does that. You can use the modbus interface to change the user settings on the charge controller if that is what you are looking for.

Can I use the python coding control it?

 

[BentleyJ]

Can I use the python coding control it?

Maybe, but you would have to use something like a RPi with a modbus TCP or RS485 expansion board (hat) or Arduino. That is way outside my scope of experience. Most on the forum are using either a PLC or Node Red which seems to have implementations for several platforms.

 

[400bird]

Can I use the python coding control it?

That depends entirely on your skill level with Python and reading the modbus map. Yes, it is possible.
However, it shouldn't be needed. The MPPT takes in as much solar energy as it can/as the battery can hold. The inverter powers the loads as needed. You shouldn't need to do anything to control the discharge. With an MPPT charging the battery, you shouldn't need to use the XW to charge as the XW charges from AC.

Equipment list:

• Schneider XW Pro 6848
• Schneider MPPT 60 100
• Schneider InsightHome
• 2.4KW battery

I assume it is 2.4kWh of storage?
That is no where near enough. How much current is the BMS rated to? If it's the typical 100 amps or less, you are just asking for problems and the BMS tripping.

 

[Eric_Li]

That depends entirely on your skill level with Python and reading the modbus map. Yes, it is possible.
However, it shouldn't be needed. The MPPT takes in as much solar energy as it can/as the battery can hold. The inverter powers the loads as needed. You shouldn't need to do anything to control the discharge. With an MPPT charging the battery, you shouldn't need to use the XW to charge as the XW charges from AC.


I assume it is 2.4kWh of storage?
That is no where near enough. How much current is the BMS rated to? If it's the typical 100 amps or less, you are just asking for problems and the BMS tripping.

I already have experience in controlling other pcs with Modbus, but my functions are: Solar Smoothing, grid frequency assistance, energy arbitrage. The first function needs to control the pcs output according to the change rate, and the second function needs to control the pcs output according to the frequency. Determine the pcs output, but the three determine the pcs output based on the time and electricity price. The 2.4kwh is just used for experimentation first and the capacity will be increased in actual use.
But currently, the register that directly controls Active Power cannot be found in the Modbus Map.

 

[Eric_Li]

That depends entirely on your skill level with Python and reading the modbus map. Yes, it is possible.
However, it shouldn't be needed. The MPPT takes in as much solar energy as it can/as the battery can hold. The inverter powers the loads as needed. You shouldn't need to do anything to control the discharge. With an MPPT charging the battery, you shouldn't need to use the XW to charge as the XW charges from AC.


I assume it is 2.4kWh of storage?
That is no where near enough. How much current is the BMS rated to? If it's the typical 100 amps or less, you are just asking for problems and the BMS tripping.

My Solar is Generator 2,I use the AC coupling

 

[400bird]

Solar Smoothing

What is this? You don't need to smooth out the solar output, just take in whatever solar you can get and cover loads.

grid frequency assistance,

Again, what is this? If you are talking about reacting to changes in grid frequency, this is handled automatically by the inverter, just chose the correct grid code.

energy arbitrage.

That is doable, but again, shouldn't require any input. Solar comes in whenever, via the MPPT and charges the battery. You can use the timer, grid support, and/or peak load shave to control how and when the inverter covers loads.

The first function needs to control the pcs output according to the change rate, and the second function needs to control the pcs output according to the frequency. Determine the pcs output, but the three determine the pcs output based on the time and electricity price. The 2.4kwh is just used for experimentation first and the capacity will be increased in actual use.
But currently, the register that directly controls Active Power cannot be found in the Modbus Map.

What is PCS?

I feel like you are trying to reinvent the wheel here or working on some "secret" project. Providing useful information this way is like pulling teeth.

There's a few different ways to control AC charge current. I assume you are trying to control AC charge current, you can't increase DC current, unless you are in charge of the sun and clouds. And I hope you aren't looking to decrease it, but that's possible.

Look at the port 502 map and search for EPC. That's what I use to control my AC charging.