We have a use case currently that require two systems to operate at a location, one of them is going to be the main and the other one as a redundant system.
So, if the main fails, the redundant will take over and work similar to main. Both the systems work onsite and would not connect to a backend instance.
I could not find a controller in openems that would do exactly like this (maybe there is one). What I understand is that the edge-to-edge controller can be used and the redundant system can be set to receive a heartbeat from the main using modbus API or REST API or mqtt subscription.
Can someone guide me if there is a controlle built-in openems that I can use and am not aware of or how should I implement this.
What exactly to you mean with “System” and what is the application (i.e. “local self-consumption optimization”, “arbitrage trading”, etc.?)
There is no built-in automated failover between two OpenEMS Edge instances, but depending on the application it might be possible to work out something via Edge-to-Edge.
Sorry by system, I mean an energy storage system. So, we have two energy strorage systems and one of them will act as a redundant system in case when the main fails.
The application is peakshaving, so the main sysetm would peakshave above a certain limit and if it fails, the redundant system will continue with the same configs as the main.
Ok, thanks. I wonder if this is an actual business case
If your concern is that one of the ESS (the battery-inverter and/or battery) fails, then it should be easy to just use a ESS Cluster. In normal operation mode the “KEEPING_ALL_EQUAL” strategy in “Ess.Power” will distribute the required power equally. In case one ESS fails, it will automatically switch over to the remaining one.
This also works via Edge-to-Edge - then you would use three OpenEMS Edge instances in total (2 x SLAVE, 1 x MASTER).
If your concern is also outage of the EMS, the network periphery, the grid-meter, etc., it becomes more complicated…
We are also considering a redundant configuration around OpenEMS Edge for grid connected battery applications. I would be happy if this is somehow valuable
Grid connected batteries (2 MW/8 MWh are popular in Japan these days) are very expensive, so it would be a waste to have the system stop due to an IT equipment failure.
Basically, we are using a full mesh topology with Ethernet. The network is automatically switched, but we are currently thinking of manually running a script to switch edges and grid meters. Automatic switching would be possible if we could determine the switching conditions, but we have not yet been able to operate it, so we have not yet reached the conditions.
Unlike IT system redundancy, it is interesting that there are very few states that need to be maintained by the computer for battery control.
