Protection Systems and Earthing Schemes for Microgrids: Main Aspects and Fault Analysis

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Filipe Bandeiras ◽  
Mário Gomes ◽  
Paulo Coelho ◽  
José Fernandes ◽  
Carlos Moreira
Keyword(s):  
Distribution Systems ◽  
Fault Location ◽  
Low Voltage ◽  
Short Circuit ◽  
Fault Analysis ◽  
Equivalent Impedance ◽  
Protection Systems ◽  
Protection Devices ◽  
Internal Faults ◽  
Short Circuit Analysis

AbstractThe content of this paper aims to assist in the development and implementation of microgrids by addressing the challenges and possible solutions for their protection systems. Therefore, an overview of some protection methods available in the literature that can be implemented to ensure a safe and reliable microgrid operation is presented, including the most common protection devices and earthing schemes that can be adopted in low voltage distribution systems. In addition, this paper also presents a brief fault analysis of internal faults at three different locations in an industrial microgrid with centralized and decentralized deployment of energy sources, as well as a short-circuit analysis of symmetric and asymmetric faults at these faulty locations. An approximate method based on the calculation of the equivalent impedance seen from the fault location is used to determine the fault currents. This study is made to observe how microgrids with different configurations perform in the event of internal faults.It is demonstrated in this work that setting a specific protection strategy to allow the microgrid to operate effectively during both operation modes can be problematic and expensive in most situations. With this in mind, additional effort is necessary to engineer and implement new protection approaches that can overcome the limitations of protection systems in future microgrids.

Line–Line Fault Analysis and Protection Challenges in Solar Photovoltaic Arrays

2013 ◽  
Vol 60 (9) ◽  
pp. 3784-3795 ◽  
Author(s):  
Ye Zhao ◽  
Jean-Francois De Palma ◽  
Jerry Mosesian ◽  
Robert Lyons ◽  
Brad Lehman
Keyword(s):  
Fault Location ◽  
Short Circuit ◽  
Fault Analysis ◽  
Small Scale ◽  
Solar Photovoltaic ◽  
Pv System ◽  
Safety Hazards ◽  
Point Tracking ◽  
Pv Inverter ◽  
Power Point

Fault analysis in solar photovoltaic (PV) arrays is a fundamental task to protect PV modules from damage and to eliminate risks of safety hazards. This paper focuses on line-line faults in PV arrays that may be caused by short-circuit faults or double ground faults. The effect on fault current from a maximum-power-point tracking of a PV inverter is discussed and shown to, at times, prevent overcurrent protection devices (OCPDs) to operate properly. Furthermore, fault behavior of PV arrays is highly related to the fault location, fault impedance, irradiance level, and use of blocking diodes. Particularly, this paper examines the challenges to OCPD in a PV array brought by unique faults: One is a fault that occurs under low-irradiance conditions, and the other is a fault that occurs at night and evolves during “night-to-day” transition. In both circumstances, the faults might remain hidden in the PV system, no matter how irradiance changes afterward. These unique faults may subsequently lead to unexpected safety hazards, reduced system efficiency, and reduced reliability. A small-scale experimental PV system has been developed to further validate the conclusions.

Control and fault analysis of multiport converters for low voltage DC distribution systems

2021 ◽  
Vol 124 ◽  
pp. 106335
Author(s):  
Simone Negri ◽  
Enrico Tironi ◽  
Gabrio Superti-Furga ◽  
Giovanni Ubezio
Keyword(s):  
Distribution Systems ◽  
Low Voltage ◽  
Fault Analysis ◽  
Dc Distribution

scholarly journals The Short-Circuit Protections in Hybrid Systems with Low-Power Synchronous Generators

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 160
Author(s):  
Bartosz Rozegnał ◽  
Paweł Albrechtowicz ◽  
Dominik Mamcarz ◽  
Natalia Radwan-Pragłowska ◽  
Artur Cebula
Keyword(s):  
Single Phase ◽  
Low Voltage ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Synchronous Generator ◽  
Synchronous Generators ◽  
Electrical Systems ◽  
Protection Devices ◽  
Short Circuits ◽  
Damage Type

Single-phase short-circuits are most often faults in electrical systems. The analysis of this damage type is taken for backup power supply systems, from small power synchronous generators. For these hybrid installations, there is a need for standard protection devices, such as fuses or miniature circuit breaker (MCB) analysis. Experimental research mentioned that a typical protective apparatus in low-voltage installations, working correctly during supplying from the grid, does not guarantee fast off-switching, while short-circuits occur during supplication from the backup generator set. The analysis of single-phase short-circuits is executed both for current waveform character (including sub-transient and transient states) and the carried energy, to show the problems with the fuses and MCB usage, to protect circuits in installations fed in a hybrid way (from the grid and synchronous generator set).

Fault location using mathematical analysis and database approach

2019 ◽  
Vol 38 (1) ◽  
pp. 415-430
Author(s):  
Sophi Shilpa Gururajapathy ◽  
Hazlie Mokhlis ◽  
Hazlee Azil Illias
Keyword(s):  
Mathematical Analysis ◽  
Distribution System ◽  
Distribution Systems ◽  
Fault Location ◽  
Research Work ◽  
Fault Analysis ◽  
Support Vector ◽  
Content Type ◽  
Adverse Weather ◽  
Continuous Power

PurposeThe purpose of this paper is to identify faults in distribution systems which are unavoidable because of adverse weather conditions and unexpected accidents. Hence, quick fault location is vital for continuous power supply. However, most fault location methods depend on the stored database for locating fault. The database is created by simulation, which is time consuming. Therefore, in this work, a comprehensive fault location method to detect faulty section and fault distance from one-ended bus using limited simulated data is proposed.Design/methodology/approachThe work uses voltage sag data measured at a primary substation. Support vector machine estimates the data which are not simulated. The possible faulty section is determined using matching approach and fault distance using mathematical analysis.FindingsThis work proposed a ranking analysis for multiple possible faulty sections, and the fault distance is calculated using Euclidean distance approach.Practical implicationsThe research work uses Malaysian distribution system as it represents a practical distribution system with multiple branches and limited measurement at primary substation. The work requires only metering devices to identify fault which is cost effective. In addition, the distribution system is simulated using real-time PSCAD by which the capability of proposed method can be fully tested.Originality/valueThe paper presents a new method for fault analysis. It reduces simulation time and storage space of database. The work identifies faulty section and ranks the prior faulty section. It also identifies fault distance using a mathematical approach.

The Application Research of Current Protection Device in Low-Voltage Rural Grid

2014 ◽  
Vol 644-650 ◽  
pp. 3675-3677
Author(s):  
Lin Yuan Wang
Keyword(s):  
Distribution Systems ◽  
Low Voltage ◽  
Power Grid ◽  
Technical Training ◽  
Protection Device ◽  
Application Research ◽  
Voltage Distribution ◽  
Effective Protection ◽  
Device Applications ◽  
Protection Devices

Current protective device against direct and indirect electric shock as well as effective protection against electrical fires has been widely used in the rural power grid, but there is also a more prominent issue. Residual current protection device in use often appearing malfunction, tripping phenomenon has seriously affected the security and stability and reliability of power supply and low voltage distribution systems. In this paper, it should be from a low-voltage distribution systems and wiring protection devices, power grid maintenance operation, standardized management products, technical training and promotion of social workers and other aspects of a comprehensive solution to this problem; and presented on the remaining current protection device applications, some of the views.

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