Reach and Operating Time Correction of Digital Distance Relay

The article considers some issues related to replacement of electromechanical relays used for protection of power facilities with microprocessor relays. One of the urgent problems connected with implementation of microprocessor overcurrent protections is how to use current transducers other than usual current transformers and in particular Rogowski coils that become more and more widespread. In the article are compared twelve methods of synthesis of a digital filter basing on the analog prototype -second-order integrating filter. The bilinear filter and Boxer-Thaler filters are analyzed in respect to their use in microprocessor relays. Basing on the research results a technique for selection of parameters of digital integrating filters for microprocessor relays is proposed. Simulation results show that Boxer-Thaler and bilinear filters have better accuracy during transient current measurements than the analog filter. The study allows concluding that in many cases the digital second-order bilinear filter is the best choice for use in microprocessor relays.

Section: Signal Sampling and Quantization In Digital Filtersmentioning

confidence: 99%

Selection of Digital Filter for Microprocessor Protection Relays

Solovev¹

2018

“…In [15], soft computing using fuzzy, genetic algorithm, Back-propagation neural network (BPNN) based algorithm is proposed for pattern identification and maximum power point. In [16] distance protection is suggested for ac systems using Rogowski coil but it has been vaildated for low voltage and lacks in high voltage. In [17] NN based contoller is used for AC/DC systems and its performance are compared with conventional controller.…”

Section: Introductionmentioning

confidence: 99%

A Novel Study on Bipolar High Voltage Direct Current Transmission Lines Protection Schemes

Agarwal¹,

Panigrahi²,

Sahoo³

et al. 2018

In long dc transmission lines identification of fault is important for transferring a large amount of power. In bipolar Line commutated converter transmission lines are subjected to harsh weather condition so accurate and rapid clearance of fault is essential. A comparative study of the bipolar system with both converters healthy and one converter tripped is studied. Most of the research paper has focussed on transmission line faults in bipolar mode but none of them had focussed when HVDC system works in monopolar mode after the fault. In the proposed scheme the voltage signals are extracted from both poles of the rectifier ends and are processed to identify the faults in transmission lines.The Artificial neural network is utilised in detecting the fault in both bipolar and monopolar system. Since it can identify the relationship between input and output data to detect the fault pattern it can be utilised under all conditions. Moreover, benefits of the proposed method are its accuracy, no requirement of the communication system as it acquires data from one end and has a reach setting of 99%.

“…With the integration of smart substations many concept of protection has been presented in literature such as wide area protection [3], [4] which protects a certain area of the grid nevertheless these concepts need a robust communication infrastructure which is not available in most cases. Furthermore, some backup Protections used to support the protection of substation based on direction comparison principle and current differential protection principle were presented [5][6][7][8] however, those algorithms are complexes to be implemented in SAS (Substation Automation System) more than that no experimental tests or prototypes have been presented. In [9] authors present a prototype based on the current differential principle scheme and IEC61850 implemented in an RTDS (Real Time Digital power system Simulation) and some special  ISSN: 2088-8708 IJECE Vol.…”

Section: Introductionmentioning

confidence: 99%

Smart Local Backup Protection for Smart Substation

Dazahra¹,

Elmariami²,

Belfqih³

et al. 2017

This paper presents a novel smart local backup protection SLBP used for the support and backup of the protective relays in a smart substation. The proposed SLBP is based on the IEC61850 standards and the concept consists of the acquisition of Generic Object Oriented Substation Event GOOSE used for tripping and interlocks exchange between Intelligent Equipment Devices IEDs and the reading of the Sampled Value SV existing in the process bus coming from Mergin Units MU or Non-Conventional Instrument Transformers NCIT. Several logical schemes to protect different zones of the substation are presented and how can be integrated using data in the substation automation system. The SLBP was developed using an open source library and free operating system. Moreover, a low cost prototype is presented in order to evaluate the efficiency and the operation of the SLBP under diverse scenarios of the proposed logical protective schemes such us breaker failure and overcurrent protection