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nickdb avatar image
nickdb asked

node red and ESS inverter limits

I have been fiddling with logic to adjust the ESS inverter limit.

The setting in the node allows a value of 0 to any value you like, but there does not seem to be a way to pass a value to disable the limit.

If inverter limits are disabled, the value read back from the node is by default 0 which means no inverting.

Any ideas how this parameter can actually be disabled instead of being left on and configured with a high value?

ESSNode-RED
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russ avatar image russ commented ·
Which node are you referring to?
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nickdb avatar image nickdb ♦♦ russ commented ·

@Russ as you can see on the GX inverter power limits are disabled:

screenshot-2022-07-26-at-132222.png

If you query this value in node red:

screenshot-2022-07-26-at-132154.png

It returns 0.

If you set the parameter to 0 then ESS enables limiting and sets it 0W, so no inverting ESS#7

There doesn't seem to be a way to set a disable flag via the same node, you can only set a high enough limit to simulate it being unlimited.

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russ avatar image russ nickdb ♦♦ commented ·
Ah, i haven't used the victron node. Since 2.9 should be available soon, i figure I'll wait till 'large' with node red is released rather than configure dbus over tcp. Pity it can't use mqtt, but I"m not really comfortable running 'mission critical' stuff on a 240v powered pi.

As to the original question, it is a mystery.

I was wondering if the disable flag was actually setting a high value but that wouldn't explain the zero value on read.

There must be some other register. Perhaps settable by mqtt?

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russ avatar image russ russ commented ·

The modbus register list has this :

com.victronenergy.settings ESS control loop setpoint 2700 int16 1 -32768 to 32767 /Settings/Cgwacs/AcPowerSetPoint yes W ESS Mode 2 - Setpoint for the ESS control-loop in the CCGX. The control-loop will increase/decrease the Multi charge/discharge power to get the grid reading to this setpoint

com.victronenergy.settings ESS max charge current (fractional) 2701 uint16 1 0 to 100 /Settings/Cgwacs/MaxChargePercentage yes % ESS Mode 2 - Max charge current for ESS control-loop. The control-loop will use this value to limit the multi power setpoint. For DVCC, use 2705 instead.

com.victronenergy.settings ESS max discharge current (fractional) 2702 uint16 1 0 to 100 /Settings/Cgwacs/MaxDischargePercentage yes % ESS Mode 2 - Max discharge current for ESS control-loop. The control-loop will use this value to limit the multi power setpoint. Currently a value < 50% will disable discharge completely. >=50% allows. Consider using 2704 instead.

Maybe there is a hint in these comments?

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1 Answer
mr-manuel avatar image
mr-manuel answered ·

To disable it just set it to -1. This works with all values that can be disabled.

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nickdb avatar image nickdb ♦♦ commented ·
Indeed, worked that out a while ago and it is working well in my flows.

Iirc at the time, pulling the value from the node used to show a 0, on current nodes it now reports -1 as expected, which is where the confusion originated.

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