The circuit is designed on basis of batteries voltage comparison with source voltage and source volt droop at the input.
Three other circuits could be designed which are on basis of ‘voltage and current’; current or output voltage of power supplies.
For the batteries health as the main source of power which must charge and discharge continuously we considered the comparison of batteries voltage with the major power sources (PV, WIND TURBINE, MAINS).
But as in the morning, we face the false voltage of PV we entered volt droop comparison in our design.
See the Process
Our circuit consists of three op amp comparators, some ZENER diodes, some rectifier diodes, resistors. Relays and battery charger.
In simulation we put a variable power supply which can be varied by letter; “A” on the keyboard for the comparator to act. For wind turbine, we put another variable source which uses letter “B” on the keyboard.
We placed normally close contact of the relay in” PV and wind turbine” path because the moment according to their priorities they fail the relay will operate and the mains which were on normally open contact will be connected.