There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The application of IEC 61850 brings significant changes to the instrumentation, monitoring, communication, control and protection systems used in the substation automation system (SAS). Compared with the conventional substation system, the implementation of IEC 61850 provides more flexibility in SAS architectures, but it also raises concerns about the reliability and performance of the overall system. This paper proposes a methodology to evaluate the reliability of an all-digital substation considering different topologies of both the station and process buses. The proposed reliability evaluation procedure is based on analytical Reliability Block Diagram (RBD) approach and stochastic Monte Carlo simulation method. This reliability analysis, combined with sensitive analysis, would help indicate the most reliable Substation Communication Network (SCN) architecture to realize a specific communication service. It would also help determine the weak points needed to be improved in order to improve the overall reliability of the automation system.

Reliability evaluation of a substation automation system communication network based on IEC 61850

Hierarchical Protection for Smart Grids

The power quality problems concern absolutely all spheres of human activity from household to economic and transport. Standardization, monitoring, management and coordination to ensure electromagnetic compatibility in the power supply system is the subject of constant, ongoing research in most countries of the world. In order to attract attention to problems of harmonics current the research focus is made on the harmonic current distortion at city's customers. The consolidation aspects of terminology, management and structure of power quality indicators are analyzed. The current and voltage waveform distortions and related harmonic components are considered in details. The systematization of the power quality indicators structure currently used by various regulations and standards was given as block-diagram. Based on quality indicators measurements taken place on existing urban infrastructure facilities, a comparative analysis with the IEEE 519-2014 standard requirements was made. As a result of field measurements analysis, an unsatisfactory situation in part of harmonic current distortions was revealed, the most probable causes and consequences of poor current quality are described.

Power Quality: Harmonic Current Distortion, Standards, Field Testing and Evaluation

The paper deals with the problem of improving the reliability of digital power supply facilities, namely digital substations. The goal of the study is to identify factors of a negative impact on the digital substation reliability indices. Based on the influencing factors analysis, technical measures for increasing reliability indexes are proposed. Based on the basic principles of the classical theory of reliability a numerical estimate of the probability of failure-free operation for the main equipment digital substation was made taken as an example the real digital substation switchgear 220 kV. Detailed equivalent circuits are given to ensure the reliability of the main units of digital substations. The numerical values of the reliability indices of the main elements are given in tabular form. The digital substation blocks with low reliability indices, as well as the most vulnerable elements of equivalent circuitry of its nodes, are identified. It was revealed that a large number of secondary circuits used in digital measuring instruments and interface devices negatively affect the reliability of digital substation units. Recommendations on maintaining the required level of reliability of power supply are given.

Estimation of Digital Substation Reliability Indices

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Expanding the functionality of automated monitoring systems for traction substations

State of the art in the tariff type selection in the retail and the wholesale electricity market for construction or reconstruction facilities located at Far East are considered. As a management solution the electricity tariff’s selection for enterprises at stage of construction or reconstruction is accented.

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Cost Reduction Ability by Electricity Tariff Selection for Construction Facilities Located in Non-price Areas

This paper deals with the basic methods for calculating reliability of electric power systems. The alternative method for determining the probability of system’s failure is offered. The principle is based on a new “compact” recording of possible routes which provide the electric power system operability. For calculating reliability parameters of the system the method of exceptions and the method of decomposition are used.

Svetlana Makasheva

Papers

Expanding the functionality of automated monitoring systems for traction substations

Cost Reduction Ability by Electricity Tariff Selection for Construction Facilities Located in Non-price Areas

Power Quality: Harmonic Current Distortion, Standards, Field Testing and Evaluation

Improving Methods for Reliability Assessment of Electric Power Systems

Estimation of Digital Substation Reliability Indices