Impacts of Ride-Through Requirements on Distributed Generation Anti-Islanding Protection

Grid codes require that distributed generation (DG) anti-islanding protection trips quickly after a loss of mains event to avoid the distribution systems' improper operation. However, as the penetration level of DG grows, the need to set anti-islanding protection to meet frequency and voltage Ride-Through (RT) requirements has become urgent to avoid unwanted DG disconnection in case of disturbances in the power system other than islanding. So, relay settings must follow RT and anti-islanding requirements, increasing the protection reliability. Thus, this paper analyses the passive anti-islanding protection functions adjusted to satisfy RT requirements for the most common disturbances in electrical systems, such as faults, loads/capacitor switching, and islanding. The results showed that the voltage block function of the frequency-based protection and a time delay setting reduced the number of incorrect operations. Besides, the short circuit level reduction contributes to a decrease in anti-islanding protection security.