scholarly journals PARAMETRIC IDENTIFICATION OF ARC-SUPPRESSION REACTOR IN THE BASIS OF INSTANTANEOUS VALUES

2021 ◽  
pp. 53-63
Author(s):  
Yuri A. Dementiy ◽  
Kirill P. Nikolaev ◽  
Rustem R. Galimzyanov
Keyword(s):  
Single Phase ◽  
Parametric Identification ◽  
Distribution Networks ◽  
Practical Application ◽  
Computing Power ◽  
Capacitive Component ◽  
Instantaneous Values ◽  
The Stability ◽  
The Mathematical Model ◽  
Influence Of Noise

Single-phase earth faults occur in 6–35 kV distribution networks. One of the devices designed to eliminate earth faults is the arc suppression reactor. The inductance of the reactor is set in resonance with the capacitance of the network, which results in the suppression of the capacitive component of the current. A method of determining the inductance of a reactor using instantaneous values of current and voltage is proposed. A differential equation linking the measured quantities is derived. The equation is written for two moments of time, and a system from which the expression for the reactor inductance is derived. Numerical approximation of the derivatives by means of the asymmetric difference derivative was carried out. The mathematical model of the reactor was composed. The influence of the asymmetry coefficient and the main parameters of the considered transients on the accuracy of determining the reactor inductance was analyzed. The influence of noise on the accuracy of determining the inductance of the reactor was considered. The influence of the main parameters of the considered transients on the stability of the method to noise is analyzed. The confidence intervals of the calculated inductance for different values of relative noise are constructed. An upgraded method for determining the detuning based on the solution of an overdetermined system of equations is proposed. The robustness of the upgraded method to the influence of noise was analyzed. The modernized method has shown to be more robust to the influence of noise in comparison with the method based on solving a system consisting of equations written for two moments of time. A test of the methods on a real oscillogram of current and voltage is described. Recommendations on the practical application of the developed methods are offered. The upgraded method is appropriate when there is a high influence of noise and no limitations on the computing power of devices, the method of calculating the inductance by two readings should be used in all other cases.

scholarly journals Application of synchronized phasor measurements in RPA devices of distribution networks

2021 ◽  
Vol 288 ◽  
pp. 01014
Author(s):  
Sergey A. Piskunov ◽  
Alexey V. Mokeev ◽  
Evgeniy I. Khromtsov
Keyword(s):  
Single Phase ◽  
Distribution Networks ◽  
Cable Line ◽  
Cable Networks ◽  
Phasor Measurements ◽  
Step Down ◽  
The Stability ◽  
Isolated Neutral ◽  
Virtual Modeling ◽  
Fast Acting

The paper discusses the efficiency of RPA devices application with support of synchronized phasor measurements (SPM) at the step-down substations and in 6-20 kV distribution networks. The main part of the paper presents a description of the algorithm developed by the authors for determining the damaged cable line during single-phase ground faults (SGF) in 6-20 kV distribution networks with compensated and isolated neutral. The proposed algorithm makes it possible to realize reliable, fast-acting, and selective SGF protection in distribution cable networks acting either on a signal or on a trip. Based on the SGF protection using SPM, an SGF localization system can be created. This makes it easier to find a damaged cable line in the distribution network. The report presents the conditions for the application of this algorithm, which ensure the stability and reliability of its operation under various parameters of the network. The paper authors propose options for improving the SGF protection algorithm, which allows expanding the field of its application. The results of virtual modeling confirm the effectiveness of SGF protection based on the SPM using the developed algorithm. The final part of the paper contains examples demonstrating other areas of SPM application for RPA devices of step-down transformers, substations, cable distribution networks.

Evaluation of the Power Transformer Magnetizing Inrush Currents

2020 ◽  
Vol 10 (10) ◽  
pp. 20-32
Author(s):  
Aleksey A. KUVSHINOV ◽  
◽  
Vera V. VAKHNINA ◽  
Aleksey N. CHERNENKO ◽  
◽  
...  
Keyword(s):  
Power Transformer ◽  
Geomagnetic Disturbance ◽  
Inrush Current ◽  
Geomagnetic Disturbances ◽  
Disturbance Intensity ◽  
Magnetizing Inrush Current ◽  
Inrush Currents ◽  
Instantaneous Values ◽  
The Mathematical Model ◽  
Analytical Expressions

The mathematical model of a shell-core power transformer’s magnetization branch is substantiated. By using the model, analytical expressions for the magnetizing current instantaneous values under the conditions of geomagnetic disturbances can be obtained. Quantitative assessments of the magnetizing inrush current amplitudes and durations versus the geomagnetic disturbance intensity are obtained. The dynamics of the power transformer magnetic system saturation transient and changes in the magnetization inrush current amplitudes and durations after a sudden occurrence of geomagnetic disturbances are shown. The error of estimating the magnetizing inrush current amplitudes under geomagnetic disturbances is determined based on comparison with experimental data.

Determining the Norton’s Equivalent Model of Distribution System with Distributed Generation (DG) for Stability Analysis

2019 ◽  
Vol 12 (2) ◽  
pp. 190-198
Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar
Keyword(s):  
Distributed Generation ◽  
Normal Condition ◽  
Distribution System ◽  
Distribution Networks ◽  
Equivalent Model ◽  
Stability Factor ◽  
Matlab Simulation ◽  
The Stability ◽  
Stability Issues

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.

scholarly journals Location of Single Phase to Ground Faults in Distribution Networks Based on Synchronous Transients Energy Analysis

2020 ◽  
Vol 11 (1) ◽  
pp. 774-785 ◽  
Author(s):  
Xuewen Wang ◽  
Hengxu Zhang ◽  
Fang Shi ◽  
Qiuwei Wu ◽  
Vladimir Terzija ◽  
...  
Keyword(s):  
Single Phase ◽  
Energy Analysis ◽  
Distribution Networks ◽  
Ground Faults

A review on phase prediction in high entropy alloys

2021 ◽  
pp. 095440622110089
Author(s):  
Vinay Kumar Soni ◽  
S Sanyal ◽  
K Raja Rao ◽  
Sudip K Sinha
Keyword(s):  
Solid Solution ◽  
Phase Formation ◽  
Single Phase ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Modeling Tools ◽  
High Entropy ◽  
Recent Developments ◽  
Phase Prediction ◽  
The Stability

The formation of single phase solid solution in High Entropy Alloys (HEAs) is essential for the properties of the alloys therefore, numerous approach were proposed by many researchers to predict the stability of single phase solid solution in High Entropy Alloy. The present review examines some of the recent developments while using computational intelligence techniques such as parametric approach, CALPHAD, Machine Learning etc. for prediction of various phase formation in multicomponent high entropy alloys. A detail study of this data-driven approaches pertaining to the understanding of structural and phase formation behaviour of a new class of compositionally complex alloys is done in the present investigation. The advantages and drawbacks of the various computational are also discussed. Finally, this review aims at understanding several computational modeling tools complying the thermodynamic criteria for phase formation of novel HEAs which could possibly deliver superior mechanical properties keeping an aim at advanced engineering applications.

The Application of Bayesian Statistics in Calculating Project Buffer

2011 ◽  
Vol 58-60 ◽  
pp. 1018-1024
Author(s):  
Feng Ye ◽  
Gui Chen Xu ◽  
Di Kang Zhu
Keyword(s):  
Bayesian Statistics ◽  
Statistical Approach ◽  
Implementation Process ◽  
Current Method ◽  
Practical Application ◽  
Great Flexibility ◽  
Crystal Ball ◽  
Simulation Results ◽  
The Stability

This paper reviews several current methods of calculating buffer on the basis of pointing out each merits and pitfalls and then introduces Bayesian statistical approach to CCS / BM domain to calculate the size of the project buffer, to overcome that the current method of the buffer calculation is too subjective and the defect on lacking of practical application. In Crystal Ball, we compare the simulation results of implementation process on the benchmark of C&PM, RESM and SM. The results show that the buffer using this method can ensure the stability of the project’s completion probability, and this method has great flexibility.

Single-Phase Generation Headroom in Low-Voltage Distribution Networks Under Reduced Circuit Characterization

2015 ◽  
Vol 30 (2) ◽  
pp. 1006-1011 ◽  
Author(s):  
Pedro M. S. Carvalho ◽  
Luis A. F. M. Ferreira ◽  
Joao J. E. Santana
Keyword(s):  
Single Phase ◽  
Low Voltage ◽  
Distribution Networks ◽  
Voltage Distribution

scholarly journals Spiking Neural Network with Linear Computational Complexity for Waveform Analysis in Amperometry

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3276
Author(s):  
Szymon Szczęsny ◽  
Damian Huderek ◽  
Łukasz Przyborowski
Keyword(s):  
Neural Network ◽  
Learning Algorithm ◽  
Waveform Analysis ◽  
Spiking Neural Network ◽  
Synaptic Connections ◽  
Practical Application ◽  
Accuracy Parameter ◽  
The Stability ◽  
Time Waveform ◽  
Network Mapping

The paper describes the architecture of a Spiking Neural Network (SNN) for time waveform analyses using edge computing. The network model was based on the principles of preprocessing signals in the diencephalon and using tonic spiking and inhibition-induced spiking models typical for the thalamus area. The research focused on a significant reduction of the complexity of the SNN algorithm by eliminating most synaptic connections and ensuring zero dispersion of weight values concerning connections between neuron layers. The paper describes a network mapping and learning algorithm, in which the number of variables in the learning process is linearly dependent on the size of the patterns. The works included testing the stability of the accuracy parameter for various network sizes. The described approach used the ability of spiking neurons to process currents of less than 100 pA, typical of amperometric techniques. An example of a practical application is an analysis of vesicle fusion signals using an amperometric system based on Carbon NanoTube (CNT) sensors. The paper concludes with a discussion of the costs of implementing the network as a semiconductor structure.

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