The overvoltage protection function of the photovoltaic inverter means that when the AC voltage of the inverter network port exceeds the upper limit of the grid voltage set by the inverter, the inverter can automatically cut off the relay of the grid port or reduce the output power to avoid damage to the electrical load in the line because of overvoltage.
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.
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).
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.
Can a PV system withstand flashes of lightning & overvoltage?
In PV systems, the PV arrays are outdoors, frequently on buildings. Depending on the situation, the inverters are also installed outdoors. For this reason, even at the planning stage of the PV system, you should determine whether measures need to be taken to deal with flashes of lightning and overvoltage.
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.
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.