Over-Frequency Derating Function; Temperature Derating - Sungrow SG1250UD Operation Manual

Operation Manual

8.6 Over-frequency Derating Function

When the system frequency deviation is bigger than f1i and the inverter active power is
bigger than the startup power Ps, the inverter will adjust the active power output according
to the frequency change.
The PV system under-frequency increase should be used together with the ESS or when
the system is under power limitation. The frequency regulation enable switch is off by
default. The relation curve between the active power and the frequency is shown in the
figure below.
Fig. 8-4 Relation curve between active power and frequency

8.7 Temperature Derating

When the ambient temperature is below 45℃, the inverter can operate at 110% of the
overload condition. When the ambient temperature reaches 50℃, the inverter can keep the
nominal power output. When the ambient temperature is above 60℃, inverter enters into
protection mode.
P(kW)
Pn
Po
Ps
fn f1i
Fig. 8-3 Over-frequency derating curve
k2
△P2
f2s f1s
△P1
k1
f (Hz)
f2i
P(kW)
Pn
Po
△P1
k1
Ps
fn f1i f2i
8. Inverter Functions
f (Hz)
43