An Analytical Survey of the Islanding Detection Techniques of Distributed Generation Systems

Abstract

This paper provides an analytical survey of the islanding detection techniques for the distributed generation systems. Islanding phenomena on takes place when the power supply from the main utility is intermittent due to numerous reasons, but the distributed generation keeps supplying power into the distribution networks. Islanding can be dangerous to workers and electrical equipment, even the power grid. Therefore, islanding detection is the priority among priorities. Islanding detection is a precondition of two working modes switching for distributed generation. In this paper, a detailed description followed by the classification of the islanding detection techniques has been made based on features, such as detection time, size of non-detection zone, power quality disturbances, system cost and operation under multiple distributed generation units. The merits and demerits of islanding detection methods are analyzed and summarized in this paper. In this manner, the greatest detection outcome can be achieved by exploiting the merits of each method. This paper is aimed to serve as a convenient reference and guidance value for deciding the islanding detection method for future islanding users in distributed generation system.

A Research of Islanding Detection Method for Distributed Generation: Mechanism, Merits and Demerits

“…These perturbation injections bring crucial change in the variables when an islanding phenomenon occurs; otherwise the perturbation is rather negligible. Active method detects, hence block the islanding activity by monitoring the variations produced by the interference [24]. The main principle of the active method is as shown in IM method measures impedance variations at the DG output in order to detect islanding activity [30].…”

“…However, these schemes substantially minimize the NDZ hence; the islanding detection efficiency is totally escalated [46]. Many of the proposed hybrid methods are still in the simulation steps, still rather far from practical application in the main utility grid [24]. The principle mechanism of hybrid method is as depicted in the chart in Fig.…”

“…4 [15]. PJD scheme will evaluate the phase difference in which is compared to the specified threshold for islanding identification [24]…”

“…A common grid, usually contains low voltage harmonics in which the standard of harmonic distortion is less than 5%, (THD<5%) [24]. However, the THD is negligible as the voltage of the grid and the PCC are match.…”

“…The merits of THD scheme is the ability to adapt in multi-inverter structure. Though, the method is afflicted by mistaken the switching of non-linear loading as islanding phenomenon [24].…”