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3
Function Description
3.1
Safety Function
3.1.1 Protection
Several protective functions are integrated in the inverter, including short circuit protec-
tion, grounding insulation resistance surveillance, residual current protection, anti-is-
landing protection, DC overvoltage / over-current protection, etc.
3.1.2 Earth Fault Alarm
The additional equipment required is a light indicator and/or a buzzer.
If an earth fault occurs, the buzzer inside the inverter will beep.
3.2
Energy Conversion and Management
The inverter converts the DC power from the PV array or the battery to the AC power, in
conformity with the grid requirements. It also transmits the DC power from the PV panel
to the battery.
With the bidirectional converter integrated inside, the inverter can charge or discharge
the battery.
Two string MPP trackers are used to maximize the power from PV strings with different
orientations, tilts, or module structures.
3.2.1 Power Derating
Power derating is a way to protect the inverter from overload or potential faults. In addi-
tion, the derating function can also be activated following the requirements of the utility
grid. Situations requiring inverter power derating are:
•
over-temperature (including ambient temperature and module temperature)
•
high input voltage
•
grid under-voltage
•
grid over-voltage
•
grid over-frequency
•
power factor (when values out of the rated values)
