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The authors suggest the concepts of protection relay systems for operation within a Smart Grid and describe the results of a prototype development. This paper introduces each of the system characteristics that should be considered for protection operation within Smart Grid, and the evaluation methods that were applied under both normal and faulted conditions. The results of a field trial in the 66kV...
Wind generation and wind farms are becoming an important part of the generating capacity of the modern utility grid. Protection of wind turbines, and wind farm collector systems, has been the subject of numerous technical papers over recent years, as wind generation grows more prevalent. These papers have focused on the basics of protecting the wind turbines, protecting the wind farm, and modelling...
This paper presents a new practical backup power supply connection scheme for Distribution Line Non-Communication Protection (DNCP). Simulation tests have been conducted using the Alternate Transient Program (ATP) with respect to a typical single circuit breaker multi-section system. Additional theoretical analysis has also been done in the condition of unsymmetrical fault on L3 to identify the variation...
The Architecture of Substation Secondary Systems (AS3) [6] is a project within National Grid Electricity Transmission which is seeking to overcome some of the ownership challenges presented by modern protection and control (P&C) devices, which have an inherent short life due to their dependence on modern electronics and software. This will be achieved by implementation of a process bus using IEC...
This work presents a new approach for a current differential protection of the transmission lines. The proposed approach is based on the Clarke-Concordia transformation and principal component analysis. First the acquired current signals are transformed into “αβo” components by applying the Clarke-Concordia transformation. This allows obtaining typical patterns. To identify these patterns a principal...
The transient transmission error of Capacitor Voltage Transformer (CVT) may cause the incorrect action of relay protection. A Novel correcting method for transient error of CVT is proposed. Using this method, CVT's primary side voltage can be calculated accurately with the secondary side voltage known. The node voltage equations based on integral equivalence is used to simplify the computation of...
This paper investigates the relationship between post fault transient overvoltages and the functionality of the numerical distance protection. The study is conducted on a 66kV network with a neutral earth resistor as method to earth the power system.
Power quality improvement has become one of the important issues because of increasing sensitive loads. For example, dynamic voltage restoration is one of the major issues about the power quality. On the other hand, a large current caused by some system fault may be unwillingly large because of many interconnections of distributed generators. A Unified Power Quality Conditioner (UPQC) is well known...
The paper discusses in detail the requirements for functional testing of devices and distributed functions used in SIPS. The methods for testing of such systems are proposed based on the testing of individual IEDs used in the system, distributed functions within a substation and between substations, complete SIPS and End-to-end testing of SIPS. Methods for the testing of complex SIPS, such as white...
Distributed generation (DG) technologies, such as wind turbines, fuel cells, and photovoltaic systems, are connected to a distribution system. A superconducting fault current limiter (SFCL) is also connected to a distribution system for fault current limitation. The connection of an SFCL causes protective coordination problems, especially for reclosing. In this work, a new reclosing algorithm is proposed...
This paper summarizes the main results of a study aimed at problem of the operation of the overhead line with inserted underground cable. Firstly the analysis of the risk of the cable insulation fault is presented and the study of protection applications follows. This study considers the situation of two cable sections inserted in an overhead line that is protected by surge arresters at both ends...
Distributed generation (DG) technologies are emerging. Nevertheless, still no sufficient strategies for active grid integration of DG units and their participation in grid control are available. Including DG units into the control of the grid state variables and into secondary grid control, would enable a variety of additional features, specially supported by the decentralized character of the DG...
Communication infrastructure in substations and control centres of Transmission System Operators should be designed in order to support variety of applications and users with different priorities and requirements. Communication requirements vary regarding capacity, maximum response times, availability, reliability and security. Up until a few years ago majority of process control systems communicated...
Advanced distance protection relays represent a significant challenge for many tasks that are performed by protection specialists during the engineering, commissioning and maintenance process due to the fact that the design and implementation of these functions varies significantly from one vendor to another. The paper analyzes the different components of a distance protection function. The modeling...
Distribution system state estimation plays major role in operational and control issues. This work executed in two stage process. The real time monitoring of distribution system simulated in first stage by PSCAD software package. RTU and power flow meters are placed at specified location identified by PSO. Monitored parameters are estimated using Swarm tuned ANN estimator, considering pseudo measurements...
IEC 61850 based substation automation systems simplify the design, installation and maintenance with significantly reduced cost. Its real-time, security and reliability are of concern and are vital important to the industry. This paper presents the development and application of an established platform for evaluating process bus applications. The evaluation platform consists of a number of GOOSE,...
In this work, a real time digital protection algorithm based on PCA and neural network methods is presented for induction motors. The proposed protection algorithm covers internal winding faults, broken rotor bar faults, and bearing faults. Many laboratory experiments have been performed on a specially designed induction motor to evaluate the performance of the suggested protection algorithm. The...
On the basis of analyzing the frequency characteristics of EHV transmission line boundary, this paper presents a novel principle and algorithm of boundary protection unit for extra-high-voltage transmission lines. The protection algorithm utilizes the improved recursive wavelet transform (IRWT) to extract the desirable frequency components of fault-induced transient signals. And then the IRWT measures...
This paper discusses special considerations that shall be taken into account when designing and deploying Ethernet networks for wind power applications. It also contains description of practical experience from a real project of a big offshore wind farms recently built and about to be put into service in United Kingdom. The paper is organized into two parts. First part describes the characteristics...
This paper presents a comprehensive simulation model for sequential tripping in DC traction system based on MATLAB/Simulink. With the introduction of practical operation of DC traction system, the scenario of “Large double end” feeding arrangement is under analysis. Based on this special scenario, the technique of simulation and protection scheme is presented. Moreover, the suggestion of setting value...
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