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

Abstract

This study proposes an islanding detection method for distributed generation systems, namely frequency fuzzy positive feedback (FFPF).The goal is to reduce the injection of disturbances, from the anti-islanding methods, during the grid-connected operation, as well as standardise the PF gain, with no adjustments needed according to the type of loads. This method is designed from fuzzy inference rules and two inputs are also considered in the design procedure. Since the classical active methods do not identify whether the frequency variation arises from the islanding condition or from a power quality issue in the grid, the fuzzy PF enables the proposed method to differentiate the islanding condition from other grid events. In contrast to classical methods that have a fixed PF gain, a dynamic fuzzy gain that adapts to any type of load 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.

Fuzzy-controlled energy storage system for improving reliability of electricity supply during islanding of photovoltaic systems

“…In this paper, a fuzzy‐based control strategy is proposed to drive the BESS such that the voltage and frequency are maintained within the statutory limits during the transition from the network disconnection to the steady‐state condition. Fuzzy logic control has been widely used in the electrical power system to solve various types of issues such as voltage rise issue, frequency control, and anti‐islanding detection . A hybrid fuzzy positive feedback system which eliminates the use of disturbance injection for the active anti‐islanding method is reported by Arguiar et al In the field of the islanding application, most of the research publications focus on the use of fuzzy logic control on anti‐islanding methods.…”

“…Fuzzy logic control has been widely used in the electrical power system to solve various types of issues such as voltage rise issue, [23][24][25] frequency control, 26 and anti-islanding detection. 27,28 A hybrid fuzzy positive feedback system which eliminates the use of disturbance injection for the active anti-islanding method is reported by Arguiar et al 29 In the field of the islanding application, most of the research publications focus on the use of fuzzy logic control on anti-islanding methods. However, the authors of 30 demonstrate that the fuzzy PID controller is able to minimise the frequency excursions much more effective than the conventional PI controller during islanded operation of the distribution networks.…”

Field programmable gate array implementation of a single‐input fuzzy proportional–integral–derivative controller for DC–DC buck converters

“…Recently, several methods have been proposed in the literature to alleviate the deficiency of the classical PID controller for power converters [7][8][9][10][11][12][13], among which fuzzy logic as a type of non-linear control technique has been utilised for DC-DC converter and other applications [14][15][16][17][18][19][20][21]. Unfortunately, the dynamic performances of the fuzzy logic controlled power converters are far from satisfactory.…”

Islanding detection method based on system identification

“…Conventional passive methods usually do nothing if the change of the detecting parameters is tiny. On the contrary, active methods, such as slip‐mode frequency shift [15, 17], Sandia voltage shift [18], Sandia frequency shift [19], active frequency drift [20], frequency fuzzy positive feedback [21], hybrid fuzzy positive feedback [22], pulse current injection [23] and negative‐sequence current injection [24] can decrease the NDZ. However, these methods introduce extra disturbances that will influence the output power quality.…”