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Multiterminal lines can be protected by distance protection and/or unit protection schemes. A well known fact of multiterminal lines, equipped with distance protection, is the inherent complexity for current in-feed and backup zone coverage. Prior to this millennium most relays (for this particular application) were unable to achieve the desired backup coverage due to limitations in zoned technologies...
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...
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...
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...
The application of numerical busbar protection technology is lagged behind that of other protection functions, although static technologies is still usual for busbar protection but the latest numerical technology provides security, dependability and much grater range of facilities.
UHV/EHV long transmission lines have large distributed capacitance and shunt reactors, which may have significant effects on the operation of a traditional distance relay. The distance relay without considering any of the above two factors will operate with serious overreaching or underreaching. Several papers have analysed these effects on the measuring impedance of distance relay and proposes different...
This paper presents a new impedance based fault location method in the case of single phase to earth faults. This method utilized the measured impedance by distance relay and super imposed current factor, which is the ratio of post-fault current to super imposed current, to discriminate the fault position on the line. This method is robust against the fault resistance. The presented method only uses...
The installation of Distributed Generation (DG) imposes many challenges in the design of distribution systems; one of which is protection coordination. Distributed generation can affect the re-closer-fuse coordination which could lead to nuisance tripping and loss of power. In this paper, the re-closer fuse coordination problem is investigated and it is proposed to use a fault current limiter to mitigate...
For a long UHV line with large distributed capacitance, the lumped parameter model of SC line is no longer valid. The apparent impedances of distance relay on series compensated line are derived and analyzed in details based on the distributed parameter model. Results show that the apparent impedances are influenced by the location of series capacitors. The sensitivity of relays is reduced largely...
This paper reports on the importance of automation of power systems in reducing power downtime after faults. Traditionally power utilities used fault calls from customers to detect power outages. Following this maintenance team would be dispatched to the scene, to first identify the location of fault and then isolate the fault area through switching activities, effect repairs and then restore power...
Since IEC 61850[1] became the widely used standard for substation communication with a lot of implementations testing is an important issue. The standard in its current version covers some possibilities and approaches for testing in general and for measurements of performance. They will be described and analysed. According to the approach of IEC 61850 the IEDs (Intelligent Electronic Devices) contain...
A new fault location method for distribution automation of active network is presented. It compares the phase angle of fault currents at both ends of a feeder section when the fault current contribution of downstream distributed generation also exceeds overcurrent setting. The measurement of phase angle is synchronized by the fault itself, and the fault is detected by comparing the current deviation...
With the increasing connections of generation using power electronics and transmission network capacity using embedded FACST devices, the measurement of higher than 50th voltage harmonics is of growing importance. This paper presents how to use the recent proposed Power Quality Sensor (PQSensor) adding onto the existing Capacitor Voltage Transformer (CVT) infrastructure to measure high orders of voltage...
This paper outlines the design challenges facing the protection and control systems required for offshore wind farms. In particular, the focus will be upon the integration of these systems and the distinct differences between the approaches taken for offshore compared to those of traditional onshore substation systems.
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 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...
It has always been a challenge to perform extensive functional tests on protection and control panels, encompassing both most likely and unlikely scenarios that could happen in a substation environment.
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