Implementation of the Improved Active Frequency Drift Anti-Islanding Method into the Three-Phase AC/DC Converter with the LCL Grid Filter

Abstract

The article presents a modified standard Active Frequency Drift (AFD) method used to detect unintentional island operation in converters generating electricity from renewable energy sources to the power grid. The primary aim of each of the island operation detection methods is the possibility of shortening the energising of a separate part of the power grid. The proposed method eliminates fragments of the reference current signal when it reaches a constant value for a particular time. This part of the signal is replaced with the hyperbolic sine function. It allows reducing the value of Total Harmonic Distortions (THD) while maintaining the same effectiveness of island operation detection. The article contains a detailed description of the newly proposed type of disturbance generation. The proposed solution is verified by conducting simulation and laboratory tests. The possibility of shortening the island operation detection time is proven by increasing the maximum distortion introduced into the current without exceeding the permissible THD limit for converters connected to the power grid.

Design and Management of High Voltage Power Systems and Insulation Materials

“…Due to limited space in devices and increasing power consumption, high-voltage power systems are required to deliver more power with smaller volume. In particular, the AC/DC converter [4] and the switch [5], as key components of high voltage power systems, are under the pressure of continuously increasing power density. Related techniques have been developed and used to improve the power density of the AC/DC converter and the switch of pulsed power with great progress.…”

Extension and Correction of Budeanu Power Theory Based on Currents’ Physical Components (CPC) Theory for Single-Phase Systems

“…Another aspect to be addressed nowadays is microgrids related to renewable energy sources [32][33][34][35][36]. Regardless of the source of electricity obtained (e.g., sun, wind, water), the whole circuit is controlled by a frequency converter.…”