I am designing a system for a 3-phase battery backup application using 3 Multiplus inverter/chargers. Where do I find information/documentation/guidelines for developing the design and sizing each unit for the 3-phase application? I have searched this web site, but most of the articles are discussing problems with a system already installed.
Also, I am currently using a Multiplus for a single-phase battery backup application and have developed a custom HMI using the VE.Bus and MK2.2 module. I know the 3-phase application requires communication between the 3 Multiplus units via the VE.Bus ports. Will I be able to continue to use one of the open VE.Bus ports for the custom HMI communication?
There is some online documentation at professional.victron.com regarding 3-phase and parallel system design but it is highly recommended you hire someone knowledgeable with these systems.
When properly set up, the three Multis appear as a single unit on the VE.Bus to a GX device or other control system via the MK to USB interface.
Thanks for the advice. I have logged in there and been “digging” for information on the 3-phase systems.
Also reviewing applications along this line – appears to be several, especially outside the US.
Yes, you can still use the open VE bus port for custom control. However, in a three phase system of any size, I think that you would be better advised to include a Venus device as the primary control, and write any custom control / interfaces under that layer. The Venus device will automate all control of the inverters, BMS and solar chargers, leaving little else that requires direct intervention. Custom interfaces can be implemented in Node red, or by writing bespoke code that integrates through the D-Bus system. This would give a far better solution than trying to implement your own code for an entire complex system. The 3 phase solution also requires pre configuration for the initial set-up.