Shifting of research trends in islanding detection method - a comprehensive survey

Dutta et al. Protection and Control of Modern Power Systems (2018) 3:1 DOI 10.1186/s41601-017-0075-8 Protection and Control of Modern Power Systems REVIEW Open Access Shifting of research trends in islanding detection method - a comprehensive survey Soham Dutta1, Pradip Kumar Sadhu1, M. Jaya Bharata Reddy2* and Dusmanta Kumar Mohanta3 Abstract The augmentation in electricity demand, power system privatization as well as efficacy of renewable resources has paved the way for power system companies and researchers to exploit the field of grid connected distributed generation (DG) and its issues, islanding being a dominant one. Several research works have been conducted to mitigate the issues of islanding detection (ID). In context of this, the paper gives a comprehensive review of islanding issues, standard test systems, criteria and shifting of research trends in islanding detection methods (IDMs). The significant contributions pertain to categorization of IDMs, evaluation of non-detection zone (NDZ) for each test system, disquisition on evolution and advancement of IDMs and its comparisons based on criteria such as NDZ, run on time, nuisance tripping percentage, applicability in multi DG system and implementation cost to draw out the strength and shortcomings of individual methods that will come to aid to the companies or researchers for establishing the applicability and appropriateness of such method for their concerned domain. Keywords: Review, Distributed generation, Islanding detection, Microgrid 1 Introduction The depletion of conventional fossil fuels at a breakneck pace and upsurge in power demand along with power market deregulation has aided in the technical and commercial development of a new paradigm in the DG all around the globe. DG means interconnection of mini or micro on-site distributed energy resources (DERs) generation with the main grid at distribution voltage stage. DERs primarily incorporate renewable and non-conventional energy resources such as solar photovoltaic (PV), hydro, wind, tidal, fuel cell, etc. [1]. Several energy market liberations and advancement in electronics and communication techniques have facilitated the operation of these geographically dispersed DERs through improved SCADA. These interconnected DERs possess the capability of operating both on-grid as well as off-grid mode. The classical structure of distribution system was passive in nature i.e. it has always considered power flow from higher voltage level to lower voltage level. Active * Correspondence: 2 Department of Electrical and Electronics Engineering, National Institute of Technology, Tiruchirappalli, Tamilnadu, India Full list of author information is available at the end of the article distribution network includes addition of DERs that are locally integrated into the low voltage distribution system that alters the network architecture and operation, rendering the classical consideration to be less applicable. The active distribution network differentiates from the passive in terms of bi-directionality of power flow, power electronics converter based generation, high fault level variability, etc. Plethoric DG penetration as well as DER placement has notable impacts on protection, operation, reliability and control of the power system [2]. These issues must be critically dealt with before permitting DG market participation for smooth operation of existing power structure along with some additional benefits like active reserve, interruptible loads, loadfollowing, restoration, etc. [3]. One of the major obstacles in redefining the existing grid structure to a smart grid structure in terms of sensitivity and stability is the concern of islanding [4]. Islanding is defined as the situation in which a fragment of the utility system is powered by one or more DG sources while that particular fragment of the system is isolated electrically from the rest of the utility system as depicted in Fig. 1. © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Dutta et al. Protection and Control of Modern Power Systems (2018) 3:1 Page 2 of 20
Equipment failure causing accidental disconnection Transformer Grid DG Circuit Breaker Load Distributed Generator 3 2 1 Loads DG2 Island Area 2 of the normal grid
Human mistake or malpractices
An act of nature In case of unintended islanding, the recent generalized industry standard is disconnection of all the DGs from the islanded portion as quickly as possible [6]. However, some IPP like BC Hydro, Canadian utility have their own requirements to comply with [7]. The undesirable consequences of unintentional islanding are as listed below which illustrates the need of unintentional ID for effective integration of DGs into existing power system topology [8, 9]:
Distributed generations are typically “weak” supplies that are incapable to handle transients efficiently.
After re-closure of the protective relays, the DGs DG1 Local Loads Island Area 1 Island Area 3 Fig. 1 Concept of islanding Island area 1, 2 and 3 is formed by opening of circuit breaker 1, 2 and 3 respectively. In light of this, the paper gives a review of IDM available in the research literature to manifest the transition of islanding detection research strategies with time. The methods have been broadly classified into classical and modern methods. A systematic analysis of these techniques is executed to bring to surface the merits and demerits of individual IDM. The rest of the paper is categorized as follows. Section 2 deals with the technical issues and concerns of islanding. The ID standards and criteria of IDM are explored in section 3 and section 4 respectively. Section 5 lays down the underlying theory, working principle and relevant equations of individual IDM. Besides, it also examines and compares various types of IDM. Finally, the work is inferred in section 6 and the future trends are discussed in section 7. 2 Technical issues with islanding Islanding can be divided into inadvertent or unintentional and deliberate or intentional islanding. Inadvertent islanding is the scenario in which islanding occurs without the prior knowledge of the utility supply or the Independent Power Producer (IPP). The grid disconnection in inadvertent islanding occurs in the following conditions [5]:
A fault that is detected by the protection mechanism of the grid but not by the protection devices installed in the grid connected DG may not be properly synchronized with that of the main grid resulting in considerable damage to the DGs as well as the utility and consumers.
If loads do (...truncated)