I have a medium size off grid system, consisting of the following:-
20Kw battery bank, 2 Multi plus inverter chargers (in parallel 240Volt 50Hz), 3 PV arrays (1Kw each),
I Venus GX system to control and report what's going on and one 11KVa stand by generator.
This system worked great but due to increasing the load by adding a deep well pump and a large irrigation system with a 1.5kw pressure pump I needed to add extra 240volt power to the system.
As the system also supplies power to another area of the property I decided to add another 4.5Kw of PV panels and a 3Kw grid tie inverter AC coupling it to the 2 Multi plus inverters and providing the whole property with a "mini Grid" which would be beneficial for future expansion.
This all works fine, the multi plus inverters controlling the output of the grid tie inverter and using the GX to limit the battery charging, all good, except!
As the multi plus units push up the frequency (50.5 or more) the washing machine goes into fault mode and stops working.
I have nearly 30 years experience in off grid installation and understand a lot about electronics. I have also travelled a lot around the world in my own yacht, fitted out with Victron inverters etc. When I arrived in South America, where the power is 240Volt but 50Hz many people in the anchorage were reporting problems with their washing machines and starting to ditch them overboard. I mentioned to a few that their problem was Frequency related and if the tried to run their washing machines on their own generators the problems would go away. This proved to be the problem and I managed to save a few people lots of money, unfortunately one German guy had already convinced himself the machine needed new parts and he had ordered them from Germany at a cost of over €1000 plus 40% import duty. He was very red faced when he started his generator and the washing machine work faultlessly!
So I have tried several things to get a steady 50hz but frequency is difficult to convert. I have already tried using a VFD and I can get a steady 50Hz even as the input varies. The VFD will not drive the washing machine though, even with a balance load connected.
At the moment my solution is to use an independent Inverter power supply just for the washing machine.
I could try and find a washing machine that is Frequency tolerant but none of the washing machine manufacturers I have contacted will talk to me the standard answer is " for health and safety reasons
please contact your local dealer". That just brings a blank look on their faces as the problem is beyond their pay grade.
So anyone got any ideas?