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This paper presents an adaptive distance protection scheme in the presence of Unified Power Flow Controller (UPFC), one of the Flexible Alternating Current Transmission System (FACTS) devices. The presence of UPFC on a transmission line has a great influence on the measured impedance at the relaying point. The measured impedance itself depends on the power system structural conditions, pre-fault loading,...
Shunt capacitor banks (SCBs) are used in the electrical industry for power factor correction and voltage support. Over the years, the purpose of SCBs has not changed, but as new dielectric materials came to market, the fusing practices for these banks changed from externally fused to internally fused, fuseless, and finally to unfused [2]. While the identification of faulty capacitor units is easy...
This paper deals with the concept development and laboratory testing of an adaptive protection system for distribution networks with distributed energy resources. Adaptation of protection relay settings according to currently available short-circuit current at respective grid nodes, is one solution to cope with the challenges originating from distributed generation. The challenges in conventional...
An effective introduction of distributed generation (DG) into existing distribution networks (DNs) calls for a review of traditional power system protection concepts and strategies. New issues such as activeness of DNs and bidirectional power flow require new protection solutions. This paper discusses protection issues and challenges arising from the integration of DG into the grid. It presents and...
Testing IEC 61850 devices is a critical part of any substation automation scheme. Many IEDs have been installed and configured to provide status and control via GOOSE messages. IEDs can also be configured to listen to sampled value data. An important part of IEC 61850 data being transmitted can be the test and quality information. Real time digital simulation using a closed loop environment was done...
Series capacitor compensation has been predominantly used to enhance bulk power transfer and stability margin between large interconnected regions by partially compensating the inductive impedance of the transmission line. Nevertheless, the installation of this advanced technology could undermine the effectiveness of some conventional line protection. This paper highlights several challenges of protecting...
System integrity protection schemes (SIPS) are being increasingly used to increase the capability of existing transmission systems. They are intended to protect the power system from catastrophic consequence of rare contingencies. Their attractiveness lies in their low cost compared to reinforcement of the transmission system or transmission curtailment to cater to the rare contingencies. This paper...
Distributed generation (DG) is recently integrating conventional power systems to assist main power plants to satisfy customer need. A control hierarchy to interconnect DG systems to conventional power systems is required to improve reliability and quality of power supply systems. The main task is to control the frequency and voltage of the systems. This task is currently done by using synchronous...
The chief advantage that the distance relay has over current-only based line protection schemes is its ability to provide a defined zone of protection without the need for a communications channel - a so-called direct tripping, under-reaching zone. This zone must operate for faults within its zone of coverage with no appreciable time delay and restrain itself for all faults beyond its reach. It must...
Based on the ratio between the sum of two terminals voltages phasor of the transmission line and the sum of two terminals currents phasor of the same line, which is defined as integrated impedance in this paper, a new ultra high voltage (UHV) transmission line pilot protection principle is proposed. When an outer fault occurs, the integrated impedance reflect the capacitance impedance of the line,...
This paper presents the development of an adaptive rule based fault identification and phase selection technique to be used in the implementation of single phase auto-reclosing (SPAR) in power distribution network with distributed generators (DGs). The proposed method uses only the three line currents measured at the relay point. The waveform pattern of phase angle and symmetrical components of the...
Developments in substation secondary systems in the future will include more and more the process bus as means to exchange data between sensor and actuators, and control and protection devices, known as Intelligent Electronic Devices (IEDs). Secondary systems will use data coming from different sensors, such as conventional current transformers (CTs) and voltage transformers (VTs) directly attached...
From the system stand point, the protective relays should operate by according with the requirements of system reliability and security, especially for overload. A smart system protection based on local information is presented in this paper, which utilizing local time-domain information to identify the flow transferring and utilizing the spatial-domain information within substation to shed load....
The goal of this paper is to coordinate directional overcurrent relays using the Evolutionary Particle Swarm Optimization (EPSO) Algorithm. EPSO Algorithm has gained a lot of interest for its simplicity, robustness and easy implementation. Coordinate directional overcurrent relays on a meshed network deals with a large volume of data, with many calculations and constraints. So that, this work shows...
This paper presents a new algorithm for faulty phase selection in transmission lines. The algorithm is based on a limited soft processing of the 3-phase and the zero-component current phasors. Current phasors are determined by using a pair of short length data window filters giving orthogonal outputs - phasor components. The soft processing means here that, generally, the operations like min and max...
Within National Grid, protection and control (P&C) design, settings and commissioning may only be undertaken by engineers who have been formally assessed and authorised, as confirmation that they possess the requisite knowledge and experience. This paper examines both the key drivers that mandated the authorisation process and the assessment model that has been developed.
Distributed generation offers the potential to maintain supplies to consumers during a system disturbance which results in the loss of grid connection. Although this is not permitted under current UK practice and there are complications from moving from a grid connected mode to an islanding mode, there are no fundamental reasons preventing their use for such a purpose should appropriate measures be...
The fault ride-through and grid support capabilities of the doubly fed induction generator (DFIG) wind turbines mainly address the design of DFIG wind turbine control with emphasis on power converters protection and voltage control issues. This paper presents the development of a protection and voltage control strategy for DFIG wind turbines, which enhances the fault ride-through capability of DFIG...
This paper proposed a method for modelling of power system fault diagnosis process. In this process, electrical power system fault diagnosis needs three kinds of information to identify fault components: protection-breaker associations, breaker-primary component (such as line, transformer, bus and so on) associations and protection-primary component associations. Firstly, the protection setting values...
This paper describes two different measuring methodology for calculating fundamental power system frequency (50 – 60 Hz) with high accuracy for numeric protection algorithms. Especially in distance protection, to measure the fundamental power frequency is a vital fact to locate the fault correctly. The problem is complex because the power frequency changes from 49.0 Hz to 51.0 Hz over a wide range...
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