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Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to increasing complexity of power systems the task of ensuring adequate operation of relay protection becomes more urgent. Detailed mathematical models of relay protection together with modern power system simulators are proposed to be used as a solution of this problem. At the same time, the adequate simulation of instrumental transformers, in particular the magnetization process of the core, is very important because the waveform of signals controlled by relay protection largely determined by transducers' errors. The developed mathematical model of current transformer reproducing the magnetic hysteresis in accordance with the Preisach theory is presented in the paper. Unlike other similar models, the Preisach' particle distribution function in the developed model is based not on the reference typical magnetizing curves, but on the volt–ampere characteristic of current transformer. This approach is better applicable in practice, since typical magnetization curves are not always available and become less relevant during transformer operation. There are presented the results of impact assessment of different types and values of burden on current transformer operation and comparison of the implemented model with existing methods of magnetization and hysteresis modeling. The adequate behavior of the developed model has been confirmed by the research. [ABSTRACT FROM AUTHOR]

Currently, an issue of relay protection (RP) settings determination that ensures its correct operation in electric power systems (EPSs) has not been resolved completely. The main reason for this is the lack of methods and tools for adequate consideration of transients during a fault existence for RP settings calculation. In this study, a novel approach for RP settings determination is presented. Its main feature is the application of detailed mathematical models reproducing simultaneously processes in the entire set of elements in the RP scheme, including instrumental transformers, and in large‐scale EPS mathematical model as a whole. This key feature can be achieved via the hybrid power system simulator – hybrid real‐time power system simulator – implementing a methodically accurate analogue–digital solution of the EPS mathematical model. The numerical transformer differential protection (NTDP) based on this approach was set up via the standard dual‐slope tripping characteristic. Also, a novel approach to the formation of the tripping characteristic is proposed. The key feature of this approach is applying a flexible curve that enveloping all fault characteristics Idiff = f (Irest) of those modes in which the NTDP should not trip. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The introduction of modern technologies significantly changes the modes of operation of electric power systems (EPS) and has an unpredictable impact on the functioning of relay protection devices (RP), in particular distance protection (DP). It is impossible to adequately measured the impact without detailed modelling of both EPS and RP devices. The subject of this research is the development of a detailed mathematical model of digital distance protection (DDP). When designing such a model, both current and voltage measuring transducers, analogue digital relay protection devices, and digital signal processing were taken into account. In this paper, studies are aimed at assessing the correctness of the third stage of the DP using the detailed and simplified model of the DDP. The operation of the compared models is tested on a 39-bus New England system via MATLAB Simulink simulation data, and a comparative assessment is provided. Such detailed DDP mathematical model in combination with an adequate EPS simulator could be used further for solution of different tasks, such as development, design, analysis, testing and setting of RP algorithms. The article presents the results of preliminary studies of the mentioned problem. [ABSTRACT FROM AUTHOR]

• Novel approach for relays tuning using detailed mathematical model. • Hybrid Real-Time Power System Simulator is used as a source of necessary data. • Proposed approach allows to adapt protection settings to practical conditions. The correct operation of relay protection (RP) devices largely determines the security of electric power systems (EPS). The key point that in turn determines the behavior of protection in various emergency modes is a determination of their settings. The existing methodologies and tools often do not allow to provide RP settings adequate to the practical conditions of their functioning. This statement is confirmed by the statistics of faults in EPSs. The main reason for this issue is the inability to reliably reproduce transients in EPS via the software programs used in practice to calculate the RP settings. The Hybrid Real-Time Power System Simulator (HRTSim), developed by the authors, allows to reliably reproduce the entire range of normal and emergency modes and processes in EPS of any scale, topology and configuration by using detailed three-phase models of all power system components. Taking into account this possibility and features of the HRTSim, the task of detailed modeling of RP devices, including instrument current and voltage transformers, becomes relevant. The implemented special tools for RP modeling and the HRTSim in general allow to develop a new methodology for RP tuning. At the same time, the typical elements – relays – can be identified for each type of RP that determine their operation algorithm. This paper presents an analysis of the main relays of the most modern microprocessor-based RP devices and proposed principles of their tuning. The developed approach allows to adapt the RP settings to the practical conditions of their functioning in EPSs and to minimize the probability of RP maloperation. [ABSTRACT FROM AUTHOR]