A New Protection System for Islanding Detection in LV Distribution Systems

Abstract

Abstract:The growth of penetration of Distributed Generators (DGs) is increasing the risk of unwanted islanded operation in Low Voltage (LV) distribution systems. In this scenario, the existing anti-islanding protection systems, installed at the DG premises and based on classical voltage and frequency relays, are no longer effective, especially in the cases of islands characterized by a close match between generation and load. In this paper, a new protection system for islanding detection in LV distribution systems is proposed. The classical voltage and frequency relays in the DG interface protections are enriched with an innovative Smart Islanding Detector, which adopts a new passive islanding detection method. The aim is to keep the advantages of the classical relays while overcoming the problem of their limited sensitivity in detecting balanced islands. In the paper, to define the requirements of the anti-islanding protection system, the events causing the islanded operation of the LV distribution systems are firstly identified and classified. Then, referring to proposed protection system, its architecture and operation are described and, eventually, its performance is analyzed and validated by experimental laboratory tests, carried out with a hardware-in-the-loop technique.

Protection Schemes of Meshed Distribution Networks for Smart Grids and Electric Vehicles

“…Zhang et al [78] propose a method for protection of closed loop, meshed networks. Finally, Li et al [79] and Fazio et al [80] investigate anti-islanding techniques and procedures.…”

Evaluation of the Use of Class B LoRaWAN for the Coordination of Distributed Interface Protection Systems in Smart Grids

“…To cope with this issue, different anti-islanding mechanisms have been recently proposed by the literature, from advanced measurement techniques, to the application of active mechanisms. A passive islanding protection method, for instance, was presented in [11], while the adoption of the traveling wave analysis was proposed in [12]. Active mechanisms have been also taken into consideration, such as the observation of the network equivalent impedance through a high frequency measure based on an intentional current injection, and the provisioning of remote signals by Distribution System Operators (DSOs) [10].…”

Assessment of Unintentional Islanding Operations in Distribution Networks with Large Induction Motors

“…1547, during unintentional islanding operations, distributed generation (DG) must be disconnected within 2 s for small voltage and frequency deviations, and in 0.16 s for significant variations [3]. Several detailed studies have been carried out to prevent islanding operations in distribution networks (DNs) in the presence of DG [4,5], and several authors have studied (intentional or unintentional) islanding operations under different contexts; see, for instance, [6][7][8].…”