Improved Active Islanding Detection Technique with Different Current Injection Waveform

Abstract

The active frequency drift (AFD) method is an effective method to detect islanding in grid-connected photovoltaic systems. However, it has some inherent drawbacks, such as generating higher harmonics. In order to reduce the harmonics and non-detection zone (NDZ), various improved AFD methods have been proposed, but they still suffer from high harmonics and reduced detection speed. To overcome these limitations, this paper proposes an innovative islanding detection technique based on AFD. Analysis reveals that the proposed method reduces harmonics by 68% compared to conventional AFD and has a larger chopping factor. Therefore, this technique offers several distinct advantages, including accelerated detection speed, reduced NDZ and harm caused by disturbances, and improved power quality. Furthermore, to verify the harmonic impact of this proposed islanding detection method, simulations and analyses are conducted using simulation software of Matlab/Simulink. An experimental prototype is set up in Laboratory. The simulation and experimental results demonstrate the superiority of the proposed method.

Bayesian Entropy Methodology: A Novel Approach to Setting Anti-Islanding Protections with Enhanced Stability and Sensibility

“…These can be subdivided into passive or active, depending on the operating hypothesis they employ [29]. Active IDMs continuously introduce perturbations at the PCC and assess the effect of these perturbations on the electric variables [30,31]. The central hypothesis behind active IDMs is that the introduced perturbation can be negligible when a DG is connected to the main grid but significantly affects sensed variables when an unintentional island is formed.…”

Progress of Optimization in Manufacturing Industries and Energy System

“…Liu et al [5] selected 31 manufacturing industries, used the stochastic frontier analysis (SFA) method to measure R&D efficiency, and used the Tobit regression method to examine the relationship between direct government subsidies, preferential tax policies and manufacturing R&D efficiency. An innovative islanding detection technique was proposed based on active frequency drift (AFD) and the analysis revealed that the proposed method reduced harmonics by 68% compared to conventional AFD and had a larger chopping factor [6]. A technology with a manufacturing working environment extending underwater was proposed for lowering the cost of installing new submarine pipelines, polluting the ocean less, and improving recycling efficiency [7].…”

Variable Reactance Criteria to Mitigate Voltage Deviations in Power Transformers in Light- and Over-Load Conditions

“…Apart from this, significant load shedding can provoke over-voltages and may even imply voltage instability [3]. Furthermore, harmonics, resonances, switching operations and faults may lead to the amplification of voltage levels due to non-linear loads, power electronic devices, insulation failures or ground faults, among others [4][5][6].…”