I am involved in an existing installation with a large pump that shares a supply transformer with two consumers houses. The inverter is a significant load and well exceeds the combined loads of the houses. The transformer is fed by a long overhead 11KV line.

When the pump is running, one house has problems with the harmonics generated by the VFD but the other does not. Both houses are fed directly from the transformer terminals with underground cables.
The inverter is fitted with DC Bus chokes and also with a coupled three phase inductor on the input.
The inverter is rated at about 70% of the transformer rating.
One solution to the problem is to install a second transformer to supply the two houses but that is an expensive option. Is there a cheaper and effective option that is guaranteed to work??