Functions and requirements of the inverter

I need to solve this problem:


Question:


For this block diagram of a PV system below I need to describe the main functions of the inverter. In your answer I have to discuss the requirements for the inverters used in PV systems.





I've already found requirements for the inverters used in PV systems.


Power electronics (inverter):

- Power conversion and conditioning

- Undervoltage/overvoltage

- Under frequency/over frequency

- Overcurrent

- Synchronization

- Ground fault overvoltage

- Active anti-island function



But could you help me with describing the main functions of the inverter and describing requirements above?