Solar inverter derating operation

What is derating a solar inverter?

Derating is the controlled reduction of the inverter power. In normal operation, inverters operate at their maximum power point. At this operating point, the ratio between PV voltage and PV current results in the maximum power. The maximum power point changes constantly depending on solar irradiation levels and PV module temperature.

How does thermal derating affect the power output of solar inverters?

Thermal derating directly impacts the power output of solar inverters. When the internal temperature of an inverter exceeds its safe operating limit, it reduces its output power to prevent overheating. This reduction can be as much as 3% for every degree Celsius above the optimal operating temperature (PV Magazine India).

Does temperature derating affect a PV inverter?

In this case, the maximum DC voltage of the inverter acts more as a technical boundary than a normal operating curve. There is no PV array operating point that requires the inverter to feed in at full power at temperatures above 31°C (at 800 V). On principle, temperature derating has no negative effects on the inverter.

What is a temperature derating inverter?

Temperature derating prevents the sensitive semiconductors in the inverter from overheating. Once the permissible temperature on the monitored components is reached, the inverter shifts its operating point to a reduced power level. The power is reduced in steps. In extreme cases, the inverter will shut down completely.