THROTTLING
As from version RPI-ECU-v3_5 we have the opportunity to set a maximum output for an inverter. This means when we set max power to 20 (wich is the minimum value), each channel produces max 20W. This means total inverter 40W.
This is an interesting feature in countries where you have to pay for power deliveries to the grid. To avoid this, we now can setup a zero-production environment and let our domotica guard it.
In the menu page there is a link 'throttling' via this you enter a webui 'throttling'. Here you can see your inverters and the configured throttle values (-1 means not available). Now choose a value for a certain inverter and save it. The debug info shows if the command was handled successfully.
if you issue the url http://ip_of_ecu/throttleAPI.php?inv=0&throttle=320 , the inverter 0 is throttled to 320.
When a message is sent like {"inverter":0,"throttle":300} to topic RPI-EVU/in, inverter 0 is throttled to 300.
With the API and MQTT commands you could automate the throttling.
You will not see the effect immediately because the inverter is polled once in 5 minutes and the power it produces is calculated as an average over these invervalls. After max 2 polls you can see in the power chart that the output stabelizes on your value.
If you want to be sure about the power settings you can go to console and use the query inverter command, this will output the maxpower as set for this inverter.
If you experience deviations in the throttle level you can calibrate the value. Go to the inverter page. Here you can fill up a THROT CAL value. This adds a percentage of the value e.g. when you throttle 200W and the calibration is 5, the value becomes 200 x 1.05. You have to (re-)throttle the inverter after this, otherwise it has no effect.
Once the value is programmed in the inverter it is retained. It means that the inverter is throttled the next day where maybe it is not needed. So it might be convenient to reset it to a high value, say 500 at the end of each day. However you should do this before the inverter goes down, well before dark.