What is Anti-Islanding Protection? Why Inverters Must Have This Function

Many solar users are familiar with the term anti-islanding protection, but few clearly understand how it works and why it matters. This post shares concise and practical knowledge for beginners.
What is islanding effect? It refers to a dangerous condition where the utility grid loses power, but the solar inverter keeps supplying electricity to local circuits, forming an independent live power zone without grid supervision.
This issue brings major hidden dangers. It may cause electric shock accidents for maintenance staff working on supposed power-off lines. Meanwhile, uncontrolled voltage and frequency will burn out inverters and electrical loads. When the grid restores power, mismatched phase and frequency will generate strong inrush current and permanently damage equipment.
As a mandatory safety feature for grid-tied inverters, anti-islanding protection real-time monitors grid status. It adopts passive and active detection methods to identify grid anomalies, cutting off grid-tied output instantly to eliminate risks.
Note that this function only limits abnormal grid-tied power generation and does not affect normal off-grid battery power supply. Never disable this protection, as it ensures personal safety and long-term stable operation of your inverter system. Feel free to comment for related questions!