Conversion & production units are not "reversible" at the moment
Summary
In the conversion unit, the energy can only flow in a unique way since the conversion unit is made of one or several consumption and production units, while in some cases it needs to flow in both ways. Moreover, there is no such thing as a reversible production unit at the moment (unit that can either produce or consume energy, such as an electrical motor).
Possible fixes
Creating new conversion units doubling units in the sense that any consumption unit will have its associated production unit and vice versa. This way, the conversion unit will be reversible.
Example : for a HV/LV electrical transformer, HV production AND consumption units are created and LV production AND consumption unit are created. The HV and LV units are respectively linked to HV and LV node, and the units are linked through typical transformer equations (efficiency for instance).
Work at the moment
This issue will be investigated in the ONIRI example available on dev_example_sh branch of OMEGAlpes examples.