15
3 Function Description
3.1 Safety Function
3.1.1 Protection
The protective functions are integrated in the inverter, including short circuit
protection, grounding insulation resistance surveillance, residual current
protection, anti-islanding protection, DC overvoltage / over-current protection,
etc.
3.1.2 Earth Fault Alarm
The inverter has integrated an earth fault dry-contact (DO2 relay) for the local
alarm. The external alarm needs to be powered by the grid.
The additional equipment required is a light indicator and/or a buzzer. The
recommended cross-section of the DO cable is 1 mm
2
.
If an earth fault occurs,
the DO2 dry-contact will switch on automatically to signal the external alarm;
the buzzer inside the inverter will also beep; and
the Ethernet communication port can be used for for transmitting the alarm
remotely.
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 array 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.
