Кафедри
Постійне посилання на розділhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/35393
Переглянути
10 результатів
Результати пошуку
Документ Problems in testing digital protective relay for immunity to intentional destructive electromagnetic impacts. Continuation of the theme(НТУ "ХПИ", 2015) Gurevich, VladimirThe article is the continuation of the theme highlighted in the previous article with same title. The new article evaluates there-sults of digital protective relays (DPR) testing for immunity to the E1 component of High-altitude Electromagnetic Pulse (HEMP) and to Intentional Electromagnetic Interferences (IEMI) impacts, conducted by some independent American organizations; discusses the features of relay protection devices as well as clarifies and supplements the procedure for testing these devices. Due to methodology errors during the DPR tests conducted by mentioned organizations earlier, they cannot be considered as satisfactory and their results as meaningful. At the moment there are no reliable data on the level of DPR immunity to IDEI, which suggests that the test should be conducted further.Документ Microprocessor protection relays: new prospects or new problems?(НТУ "ХПИ", 2006) Gurevich, VladimirThe internal architecture and principles of operation of microprocessor-based devices including so-called "microprocessor protective relays" have little in common with devices called "electric relays". But microprocessor-based relay protection devices are gradually driving out the traditional electromechanical and even electronic relay protection of virtually from all fields of power and electrical engineering. Advantages of microprocessor-based protection means over traditional ones are far from being absolute or obvious, yet this is a general trend. In reality, however, microprocessorbased protection means have several specific 12 drawbacks too. In this paper, some of these problems are discussedДокумент Nonconformance in electromechanical output relays of microprocessor-based protection devices under actual operating conditions(НТУ "ХПИ", 2006) Gurevich, VladimirMicroprocessor-based protection relays are gradually driving out traditional electromechanical and even electronic protection devices from virtually all fields of power and electrical engineering. In this paper, one of many problems of microprocessor-based relays is discussed: nonconformance of miniature electromechanical output relays under actual operation conditions: switching inductive loads (with tripping CB coils or lockout relay coils) at 220 VDC, and "dry" switching of some control circuits. We suggest a simple and very reliable solution to this problem: an electronic amplifier for increase in switching ability of the output relays.Документ High current pulse transducer for metal-oxide surge arresters(НТУ "ХПИ", 2007) Gurevich, VladimirHigh-voltage arresters of 160 kV and higher voltage types based on zinc-oxide varistors are important and expensive devices. The main imperfection of existing devices for the varistors monitoring is necessity of human intervention to work with them. A simple automatic high-current pulse transducer included in SCADA system by means of a radio transmitting-receiving set and intended for the arresters control is introduced.Документ Simple very high-speed overcurrent protection relay(НТУ "ХПИ", 2007) Gurevich, VladimirПриведено описание и представлены результаты экспериментальных исследований быстродействующего гибридного реле тока с чувствительным органом на герконе. Показано, что такое реле может быть с успехом использовано для ускорения действия основной релейной защиты.Документ Problem with output relays used in microprocessor-based protection devices: what to do?(НТУ "ХПИ", 2007) Gurevich, VladimirIt is the author's second publication on nonconformance of parameters of subminiature output relays used in microprocessor-based protective devices to actual operation conditions and standards. The article suggests adjustment of the standards and presents specific engineering solutions to this problemДокумент A Problem of Power Supply of Microprocessor-Based Protective Relays at Emergency Mode(НТУ "ХПИ", 2007) Gurevich, VladimirThe paper discusses a problem of power supply for microprocessor-based protective relays in a substation with AC and DC auxiliary voltage in an emergency mode. The paper recommends application of power capacitors and supercapacitors instead of UPS as energy storage elements for short-time duration feeding of protective relays in emergency modes.Документ RCD nuisance tripping: who's guilty and what needs to be done?(НТУ "ХПИ", 2013) Gurevich, VladimirThe reasons for nuisance tripping of residual current devices(RCD) are analyzed in the article and the affect of many external factors isdiscussed. Solutions are described for avoiding faulty tripping of an RCD.Документ The issues of philosophy in relay protection(НТУ "ХПИ", 2013) Gurevich, VladimirPhilosophy beginning with the ancient Greeks is literally "a love of wisdom" and deals with the most general issues of reality. The Wikipedia dictionary determines philosophy as a science, which studies everything. Logic and critical analysis are the pillars of philosophic thinking. ‘So, why don’t we use these attributes of philosophy to analyze the situation around relay protection,’ – Dr. Vladimir Gurevich raises this question, and it appears that such analysis may result in counterintuitive findings.Документ A new criterion needed to evaluate reliability of digital protective relays(НТУ "ХПИ", 2012) Gurevich, VladimirThere is a wide range of criteria and features for evaluating reliability in engineering; but as many as there are, only one of them has been chosen to evaluate reliability of Digital Protective Relays (DPR) in the technical documentation: Mean (operating) Time Between Failures (MTBF), which has gained universal currency and has been specified in technical manuals, information sheets, tender documentation as the key indicator of DPR reliability. But is the choice of this criterion indeed wise? The answer to this question is being sought by the author of this article