Islanding detection is one of the essential features for photovoltaic grid-connected systems; detection performance is directly related to safe operation of the equipment. Summarize existing islanding detection, then an active method based on frequency – reactive power feedback islanding detection is proposed. Once an islanding condition occurs, the method introducing a load frequency reactive ...

Penetration of distributed generation in the power grid is increasing. This situation leads to new possibilities but also new issues, such as anti-islanding protection. During a loss-of-mains or islanding situation, distributed generation (DG) units remain feeding a part of the electrical network without connection to the main power system. Currently, DG units have to be disconnected from the g...

Islanding is the situation in which part of the power grid, consisting of load and distributed generation (DG) is isolated from the utility grid remaining active, i.e. serving load. The idea of islanding parts of the distribution network in case of faults, in order to increase the consumer quality of service, is the basic notion behind the formation of Microgrids. In the context of Microgrids, ...

In this paper Islanding detection methods for distributed resources are reviewed. The mainly used islanding detection techniques may be classified as active and passive techniques. Passive techniques don’t perturb the system but they have larger nondetection zones, whereas active techniques have smaller nondetection zones but they perturb the system. In this paper a new hybrid method is propose...

Existing control techniques for DG systems are designed to operate a system either in the connected or disconnected (islanding) mode to the utility; thus not allowing for both modes to be implemented and transitioned between. Existing detection and re-closure algorithms can also be improved upon. Dependent upon the method implemented, detection algorithms can either cause distortions in the out...

UOVR and UOFR as passive anti-islanding methods lack of sensitivity to detect islanding. The performance gets worse when the frequency threshold is increased from 50.2 Hz to 50.6 Hz. For instance, dedicated passive methods such as ROCOF help the inverter to detect islanding. When active methods such as SFS and SVS are activated, the number of detected islandings is increased to 87.5%. To improv...

The connection of inverters for distributed generation photovoltaic systems to the distribution network creates situations of risk to the loads that are connected to the point of common coupling (PCC) and personals who maintain the power grid. A risk that should be avoided is the supply of electricity, by one or more inverters, to the distribution network after disconnecting the main power grid...

This paper proposes active frequency drift (AFD) as an anti-islanding method applied to micro-inverters with uncontrollable reactive power. When using ordinary inverter topologies, such as full bridge inverters in photovoltaic systems, the islanding phenomenon can be detected with reactive power-based methods, such as reactive power variation. However, when the inverter topology cannot control ...

Islanding detection is a necessary function for grid connected distributed generators. Usually, islanding detection methods can be classified as two catalogues: remote detecting methods and local detecting methods. Most of them have limitation and defects when they are applied in photovoltaic power stations. Recently synchronous phasor measuring units (PMU) is proposed to be applied for islandi...

The mainly used local islanding detection methods may be classified as active and passive methods. Passive methods do not perturb the system but they have larger nondetection zones, whereas active methods have smaller nondetection zones but they perturb the system. In this paper, a new hybrid method is proposed to solve this problem. An over/undervoltage (passive method) has been used to initia...