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In this paper a novel numerical algorithm for locating faults on transmission lines will be presented. The algorithm does not need the line parameters to locate the fault and can locate all fault types, which makes it very different to existing fault location methods. Line parameters are known only approximately and they differ with varying loading and weather conditions, so an algorithm that does...
This paper presents a new multi-ended fault locator algorithm which uses line current differential relay synchronized measurements of currents and voltages, applicable to both 2-and 3-terminal lines. The described algorithm is executed separately at each terminal and the result is available at each terminal immediately after fault.
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...
Due to the fact that wide area information is easily disturbed, lost and distorted, while it is not fully considered in current wide area protection principle, a wide area backup protection algorithm with high fault-tolerance performance is proposed to implement the CSBPS(Centralized Substation Backup Protection System). After the fault-tolerance judgment, The CSBPS can locate the fault equipment...
In this paper, a chirp detector of the current waveforms is evaluated for locating the earth faults in unearthed MV networks where it is used to precisely localize the travelling wave arrival times created by the fault occurrence. Chirp modulation, or linear frequency modulation employs sinusoidal waveforms whose instantaneous frequency increases or decreases linearly over time. These waveforms are...
This paper presents an assessment of the performance of distance protection for transmission lines in the presence of Quadrature Booster Transformers (QBs). The use of QBs in the UK transmission grid is increasing to maximise the utility of existing infrastructure as well as enabling rapid network modifications as dictated by operational requirements. An analysis is performed with the aid of a real...
This paper proposes a new protection scheme for transmission lines equipped with UPFC based on the synchronized phasor measurements at both ends of the line. The fault detection and location indices based on sequence components are derived and used to discriminate the internal and external fault events accurately. The time for identifying an internal fault is well below 1/2 cycle. The performance...
This paper presents a novel solution for the protection of high-voltage power cables based on differential protection principles with currents measured by Rogowski Coil current sensors. This solution has been designed for implementation on four in-service 220 kV power cables that interface a gas-insulated substation (GIS) with overhead transmission lines. The protection scheme has been subjected to...
State estimation is an important tool for power system supervision and control and the related applications. Based on the redundant measurements taken in the network, state estimation provides the most likely state of the power system. Conventional measurements were collected by the SCADA system and the measurement chain did not allow measurement synchronization. A disadvantage is that due to the...
This paper describes design of an integrated numerical protection scheme for two pump-storage generator/motor-transformer units. Regardless of the application complexity, the complete protection scheme for one unit can be integrated within a single numerical multifunctional IED.
In 2008 National Grid (UK) implemented a new relay settings process and database system both to facilitate the management of relay settings sheets associated with Multi-Functional Numerical Relays (MFRs) and to ensure the correct application of settings on protection relays on site. This paper describes how this new process and database system enables a reduction in the number of settings sheets,...
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...
Underground distribution cables are usually characterized with different technical difficulties regarding detecting and locating their faults. Different factors participate into these difficulties including their remarkable charging currents, cable construction and variations of their equivalency resulted from the variety of bonding and grounding methodologies. In this paper, a new fault location...
As the existing transmission system infrastructure is challenged to support loads beyond original design limits, the implementation of “wide area” Power System Protection Systems (PSPS) also called System Integrity Protection Schemes (SIPS) are often needed to maintain transmission system integrity. Such a system, with stringent performance and availability requirements, has been designed and installed...
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.
To date, the skin effect has not been considered in the analysis of network fault response and the design of protection systems for DC networks. However, the naturally high resonant frequencies of some modern marine and aerospace electrical networks under electrical fault conditions suggest that skin effect should be investigated more closely. The studies reported in this paper compare the system...
The phenomenon examined in this paper are some of the most difficult conditions for distance protection, but by no means an exhaustive list. The strength of Distance protection lies in making reliable decisions using only local measurements. The measures taken are as diverse as the conditions considered. As far as possible the methods recommended in this paper use local measurements to stabilise and...
In industrial installations typically end users want to take advantage of the transformer differential protection or the line current differential protection in order to protect with a single system, relative short portions of cable lines, usually in the range of 10 km, that feed power transformers. The protection requirements for cable line and for transformer are different, thus protection scheme...
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