How does an islanding solar inverter work?

Your islanding solar inverter works independently from the power grid. If there's a storm or other event that knocks out the main power grid, your solar power system will continue running and providing power to your home. We mention this because many people mistake going solar with going off-grid, but that's typically not the case.

What is islanding in a single-phase grid connected inverter?

In some cases, islanding is intentional. When this occurs, the inverter detects the grid event and automatically disconnects itself from the grid, creating an island intentionally. The single-phase grid connected inverter is then forced to push power to the local circuit. This method is used as a backup power generation system.

How does an anti-islanding inverter work?

By looking for deviations in zero-crossing, frequency, or voltage of the grid waveform, an anti-islanding inverter can detect loss of power in the grid and disconnect itself from the grid when islanding occurs. In such a case, the relay needs to be opened quickly when islanding is detected (or when the inverter otherwise enters a fault condition).

Why is my inverter causing an island?

The affected area is identified as an island because it is surrounded by lines that are not delivering power. In some cases, islanding is intentional. When this occurs, the inverter detects the grid event and automatically disconnects itself from the grid, creating an island intentionally.

How does an inverter detect an islanding condition?

When the measured characteristic falls below threshold values, the inverter determines that an islanding condition exists and either shuts itself down entirely or disconnects from the grid while continuing to power the local load. The most common passive anti-islanding methods take advantage of a key mechanism in inverters.

Do inverters have anti-islanding protection?

If you hear someone say their inverter is fitted with anti-islanding protection, it simply means it has islanding detection (often based on voltage and frequency detection) and detects when the grid is down. That way, it stops feeding power back to the grid and protects utility workers.