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Travelling wave (TW) differential protection fully utilizes the fault information contained in TW at both terminals of a transmission line, so it's a protection with high reliability and high selectivity. However, because TW differential protection needs a large amount of communication, it cannot be put into practical use. This paper proposes a TW differential protection which is based on equivalent...
To solve the difficulty that existing analysis methods cannot get complete analytic solution of fault-induced travelling-wave on transmission line, an analysis method is presented in this paper, which decomposes fault-induced travelling-waves into non-stationary component and stationary component and then get the approximate analytic solution of stationary component. Non-stationary component reflects...
Large parts of the legacy Scottish Power Transmission (SPT) networks have reached their thermal limits in terms of accommodating any further generation and still a significant amount of new embedded generation is being contracted for connection across the Scottish Power Transmission and Distribution networks (SPT and SPD). To accommodate further generation substantial network reinforcements and network...
This paper presents an investigation of the impact of multi-generator power islands on the performance of the most-commonly used anti-islanding protection method, Rate of Change of Frequency (ROCOF). In particular, various generating technology mixes including Photovoltaic panels (PV), Doubly Fed Induction Generators (DFIGs) and Synchronous Generators (SG) are considered. The Non-Detection Zone (NDZ)...
The focus in this paper is on development of voltage vector shift (VVS) based passive islanding detection as a part of grid code compatible combined islanding detection scheme or alone as a back-up for combined scheme. Islanding detection during utility grid frequency fluctuations could be made more reliable and also non-detection zone (NDZ) could be reduced with VVS based combined scheme if sensitive...
Based on the existing active islanding detection method known as power disturbance, an adaptive power disturbance (APD) method is proposed. This method calculates the minimum power disturbance value required to effect islanding detection based on the relationship between the voltage at the point of common coupling (PCC) after islanding and the power generated by the inverter. The conventional passive...
This paper illustrates how converter interfaces, used to connect renewable energy sources, HVDC links and infeeds to the power system, may bring significant changes to the behaviour of protection systems in the future. A converter model, capable of providing adjustable fault responses, is used to investigate the response of power system protection to a range of fault conditions. Different scenarios...
The significant penetration of Distributed Energy Resources (DERs) and their sensitivity to voltage sags during short circuit faults requires changes in the protection schemes at the transmission and distribution level in order to ensure reduced fault clearing time which will help with the ride-through capability of the DERs when a fault occurs. The paper presents methods for accelerating the protection...
The main aim of this research work is to assess the impact of wind farm integration on existing electricity grid in UAE and its protection system. The case study considered in this research work is 132 kV Dubai transmission network. The grid integration model was built using MATLAB Simulink software including grid parameters and 1.5 MW doubly-fed induction generator (DFIG) model. The DFIG generator...
In order to assess their use for metering purposes, a set of tests have been conducted on various commercially available Stand Alone Merging Unit (SAMU). After a brief general overview of the principle of SAMU, some innovative test approaches and their results are presented in this paper. Impact of accuracy and synchronisation is discussed. Special care has to be taken for accurate time synchronization...
With the electrification of the Great Western route, one of Britain busiest railways, Network Rail will install the new Rationalized Autotransformer System (RATS) at over 50 substations for the first time. The conventional 25-0-25 kV autotransformer electrical traction system will be rationalized by introducing Load Break Switches in place of circuit breakers at the autotransformer sites. To detach...
The GB transmission network faces the combined challenges of an aging installed asset base and a major shift in the generation profile towards renewable resources. Due to cost, outage times and other constraints, planning and executing the necessary transmission refurbishment and reinforcement is fast becoming a major challenge. For operational reasons, transmission outage schedules are restricted...
This paper discusses the objectives, delivery and learning from the Electricity North West Limited (ENWL) Customer Load Active System Services (CLASS) project, funded via Ofgem's Low Carbon Networks (LCN) Fund. CLASS project identified the need to explore the ability of Great Britain (GB) distribution networks to deliver a suite of network services; in support of National Grid (NG)'s responsibility...
The principal characteristic of a traction system is its moving load, and its property of occurring at any point along a traction feeder. For traction feeder faults, a known risk exists of a train entering, or “running-in”, a faulted section at the time of the fault. The train briefly bridges the insulated overlap, section gap or section insulator, and hence bridges the fault path to an adjoining...
Distributed energy resources (DER) impact the load flow and short circuit levels in distribution systems. Therefore, important considerations in order to have a secure DER integration to the electrical systems must be analysed. This integration involves great technical challenges, both to the DERs, as well as to the electrical grid. Potential problems like stressed duties imposed on breakers, out...
The main contribution of this paper is a description of a formal method and tool to estimate the expected changes of power system performance and reliability indexes, due to the contribution of wide-area protection and monitoring schemes (WAMPS). The resulting model is capable of estimating their impact to not only grid resilience and inoperability, but also reliability and availability metrics, like...
In this paper, strategies and techniques applied to IEC 61850 based DSAS architectures are presented and discussed with the perspective of obtaining high levels of reliability, availability and efficiency. Practical issues and implementations are considered. A suggestion of a way to be followed in order to reach real and effective WAMP AC S systemic functions is described.
Statnett use frame agreement with a few vendors to ensure uniform protection and control systems on a proven basis of a pilot project. Statnett have requirements to protection in the specification that the vendor must fulfil. The vendors adapt their protections to fulfil the requirement from the specification. Statnett use a control server where documentation for all the plants are stored. The control...
The electric power grids and power systems are critical infrastructure parts of our modern society and are ascertained by high demands on reliability and stability. At the heart of these intelligent grids we find specialized IT systems, such as substation automation systems. These systems are following standards and trends, as of which one of them is in particular Ethernet and TCP/IP based communication...
Because of the distinct characteristics of Korean AC railway system, research about localization of protective schemes of equipment for Korean railway system in domestically has received attention. In order to establish the protection schemes, circuit analysis of railway system is required. We used an inductive analysis method for circuit analysis and produced results concerning the fault current...
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