Hybrid inverter with solar battery charging system using microcontroller

Concept of model

Two renewable energy sources that is utility grid and solar are incorporated with
inverter along with micro-controller to design hybrid inverter. The first priority
is given to the utility grid and then to the solar and last to the battery to supply
the loads. Suppose, the threshold voltage for micro-controller to compare between
solar and grid is 9 volts. If the voltage of the utility grid is greater and equal to
threshold voltage, micro-controller switches to grid and at that time solar energy is
used to charge the battery. When power cut off occurs at the grid, solar supplies
power to the loads. At night or cloudy weather,no solar energy is sufficient to
charge the battery in such case grid supplies the battery as well as to the loads.
When both solar and grid is not available, battery supplies power to the load.