Microprocessor protection relays: new prospects or new problems?

The 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 discusse

Simple very high-speed overcurrent protection relay

Приведено 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

Peculiarities of the relays intended for operating trip coils of the high-voltage circuit breakers

Parameters of the subminiature electromagnetic relays used as output elements in microprocessor relay protection, do not correspond to technical specifications on these relay protection. The reasons of this discrepancy are analyzed. Contradictions and discrepancies of the international standards in this area are considered. It is shown, that absence of clearness in standards and mistakes in technical specifications of manufacturers of microprocessor protection do not allow estimating correctly technical parameters and lead to decrease in reliability of relay protection

Problem with output relays used in microprocessor-based protection devices: what to do?

It 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 proble

High current pulse transducer for metal-oxide surge arresters

High-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.Высоковольтные разрядники класса 160 кВ и выше на основе оксидно-цинковых варисторов являются ответственными и дорогостоящими аппаратами. Главным недостатком известных устройств для мониторинга варисторов является необходимость участия человека в работе с ними. Предложен простой,полностью автоматический датчик импульсных токов для контроля разрядников, включенный в систему SCADA посредством комплекта радиопередатчик-приемник

A Problem of Power Supply of Microprocessor-Based Protective Relays at Emergency Mode

The 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.Рассматривается проблема электропитания микропроцессорных устройств релейной защиты на подстанциях с переменным и постоянным оперативным напряжением в аварийных режимах. Рекомендуется использовать конденсаторы большой емкости и суперконденсаторы в качестве накопителей энергии для кратковременного питания защитных реле в аварийных режимах

Protection of Telecommunication Systems in Electric Power Facilities from Electromagnetic Pulse (EMP). Part 2.

A communication system installed at an electric power facility performs the critical role in data acquisition and transmission, remote measuring and control, and communications. At the same time, it is most sensitive and the least protected from the high-altitude electromagnetic pulse (HEMP) amongst the wide variety of other critical electric and electronic systems used at the power facilities. Such a situation should not be considered as normal; instead it requires the appropriate measures to be taken. This article is an extension to the discussion of this problem started in the previous article [1]. It describes the common technology and element basis used for protection of communication system equipment

Establishment of Inventory of Electronic Equipment Replacement Modules as a Way to Improve the Survivability of the Power System

The article discusses a way to improve the survivability of the power system affected by the High Altitude Electromagnetic Pulse (HEMP) through establishment of inventory of electronic equipment replacement modules, particularly those of digital protective relays. It is shown that the known methods of spare parts quantity optimization cannot be used in this case. Thus, another method is offered. Specific principles of the storage of replacement modules are discussed as well as the ways of their realization

Protection of Telecommunication Systems in Electric Power Facilities from Electromagnetic Pulse (EMP). Part 1.

Telecommunication systems of electric power facilities play an important role in data transmission, telemetry, remote control and communication. At the same time, these systems are the most sensitive to, and the least protected from, High Altitude Electromagnetic Pulse (HEMP), compared to other important electric and electronic systems used in the electric power industry. This situation cannot be perceived as normal and thus calls for corresponding actions. Unfortunately, renowned technical means are often very expensive, and regardless of advertisement, claims they do not always ensure reliable HEMP-protection of telecommunication systems. An analysis of the situation and a new solution for the problem is presented in this article

A NEW CRITERION NEEDED TO EVALUATE RELIABILITY OF DIGITAL PROTECTIVE RELAYS

Для оценки надежности в технике существует целый набор различных критериев и параметров, однако, для оценки надежности цифровых устройств релейной защиты (DPR) выбран один из них: «наработка на отказ», который получил повсеместное распространение и указывается в технической документации, рекламных проспектах, тендерной документации как основной показатель, характеризующий надежность DPR. Но насколько оправдан выбор именно этого критерия? Ответ на этот вопрос пытается найти автор данной статьи