Latest Export Requirements For Photovoltaic Inverters

What is a fast overvoltage protection mechanism?

Inverters, whether used for photovoltaic (PV) systems or energy storage facilities, typically include internal fast overvoltage protection mechanisms designed primarily to protect the inverter itself from damaging transients.

What is overvoltage protection?

Overvoltage protection serves to prevent damage to electrical and electronic devices as a result of excessive voltages. Overvoltage protection devices (surge protection devices, or SPD for short) generate equipotential bonding between the connected conductors when excessive voltage is applied.

Can overvoltage protection devices be retrofitted?

The overvoltage protection devices can be retrofitted by plugging them into the base which is standard on all devices. In the Sunny Tripower, the medium protection can be retrofitted quickly and cost-effectively thanks to the SPD type II which can be integrated.

Why is the protection level at the inverter increased?

In addition, the protection level at the inverter is increased if the overvoltage occurs at one of the other strings. When excessive voltage is applied, voltage falls via the cable inductance. If the arrangement is not ideal, the protection level at the inverter is increased (see Fig. 6).

Can external grounding transformers reduce overvoltage in inverter based systems?

Transient overvoltages during single-line-to-ground faults are often mitigated by introducing external grounding transformers in traditional synchronous generator based power systems. These external grounding transformers are relatively ineffective for mitigating overvoltages in inverter based systems.

How to protect an SMA inverter from overvoltage?

If you wish to protect an SMA inverter against impacting overvoltages, an SPD type II is sufficient. If lightning partial currents are expected, an SPD type I with connected SPD type II should be used. For inverters with one MPP tracker, the strings are combined before the inverter and connected to the SPD(s) at the point of interconnection.