Power Derating - Sungrow SH5K-20 User Manual

3 Function Description

3.2.1 Power Derating

Power derating is a way to protect the inverter from overload or potential
faults. In addition, the derating function can also be activated following the
requirements of the utility grid. Situations requiring inverter power derating
are:

grid dispatching

over-temperature (including ambient temperature and module temperature)

grid under-voltage

export power limit setting

power factor (when values out of the rated values)
Grid Dispatching Derating
Adjust the output power according to the remote scheduling instructions and
the inverter operates with the power derating.
Over-temperature Derating
A high ambient temperature or poor ventilation will lead to a power derating of
the inverter.
When the internal temperature or module temperature exceeds the upper limit,
the inverter will reduce the power output until the temperature drops within the
permissible range.
Grid Under-voltage Derating
When the grid voltage is too low, the inverter will reduce the output power to
make sure that the output current is within the permissible range, as
calculated by the following equation.
When Vmin < V < 230 V, P = Pn ×(V
Refer to "12.3.1 Volt-watt Response" for over-voltage curve. The following
figure shows the under-voltage derating curve.
16
/ 230 V)
grid
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