Hybrid fuzzy anti‐islanding for grid‐connected and islanding operation in distributed generation systems

Abstract

This study proposes a method for islanding detection in distributed generation systems, namely, hybrid fuzzy positive feedback (PF). The aim is to reduce the injection of disturbances during the grid-connected operation from the anti-islanding methods, particularly at the instant of load connection and, do not require adjustment of the PF gain and frequency filters. This method is designed from fuzzy inference rules and the frequency and voltage inputs are also taken into account in the design procedure. Since the classical active methods do not identify if the voltage variation arises from the islanding condition or from a power quality issue in the grid, the fuzzy PF enables the proposed methods to differentiate the islanding condition from other grid events. In contrast to classical methods that have a fixed PF gain, a dynamic fuzzy PF gain is obtained by means of the fuzzy inference rules. The classical active technique is compared with the proposed approach in terms of detection time and injected disturbances during the grid-connected operation. The simulation and experimental results are presented to demonstrate the effectiveness of the proposed approach.

Evaluation of an interleaved boost converter powered by fuel cells and connected to the grid via voltage source inverter

“…The procedure used in both control modes, consists of starting the system in stand‐alone mode until the ac voltage produced by the VSI is in synchronism with the grid, according to the phase‐locked loop (PLL) algorithm. After the synchronisation, the relay is switched on and the system starts operating in grid‐connected mode [30].…”

An Adaptive Power Sharing Control for Management of DC Microgrids Powered by Fuel Cell and Storage System

“…In the most of them, the FCs are a part of the dc microgrid where the use of SSs, PV arrays and wind generators improve the system stability, capability of power production and power quality, respectively. Additionally, this type of solution is known as hybrid integration and it can be connected to the main grid or operate in standalone mode [5], [6].…”

Grid Connected Inverter for Current Control by Using Anti-Islanding Technique

“…However, since the indirect current control does not make the magnitude and frequency of voltage across the load vary when an islanding occurs, the conventional anti-islanding method such as the reactive power variation (RPV), the magnitude and frequency positive feedback and the active frequency drift (AFD) based on the magnitude and frequency of voltage variation cannot be applied to the indirect current control [11][12][13][14][15]. The harmonic injection antiislanding method can detect the islanding, but it may cause a severe distortion in current and voltage of the critical load [16][17][18][19][20]. In this paper, an islanding detection method for the indirect current control is proposed.…”