/Length 15 0 R << TYPES OF RELAY INTRODUCTION TO PROTECTIVE RELAYING WHAT IS PROTECTIVE RELAYING? control test switch 8781 34.5 w bus differential relay sel-587z sel relay control test sv.qrch 2ts12 sÉl-587z high-impedance differential relay schweitzer engineering laboratories relay control test switch 2ts13 . 2 0 obj protection shape) of distance relays is the mho characteristic, a circular type reach characteristic. Normal operation - It involves requirements for supplying the existing load and a certain amount of anticipated future load. /Filter /FlateDecode See also: relay. endobj In the middle you see a cloud with an icon you probably haven’t seen before. �;�%�����������Yg¸�����������&�����������Yj¸�����������6_�|�3Z��\53333333333j��K�7���a|o����G�'����/ �dr���ߎ��������OW������ �v~~����G+\J?zto2��&. >> The factors affecting the choice of protection are type and rating of equipment, location of the equipment, types of funks, abnormal /Subtype /Image 54 Break-before-make Contacts. /Type /XObject << /Width 1971 UNIT I - INTRODUCTION OF RELAYS. endobj 'OF�c��a� �Og�x02|�9�5C�0�*�CqtjTU{���b�������*2 �p�R�Dv�k%6V�[��F:�i$��*���nɈI�6x��0:�6. 18 FUNDAMENTAL RELAY-OPERATING PRINCIPLES AND CHARACTERISTICS Time delay is obtained in induction-type relays by a "drag magnet," which is a permanent magnet arranged so that the relay rotor cuts the flux between the poles of the magnet, as shown in Fig. /ColorSpace /DeviceGray Relays are remote control electrical switches that are controlled by another switch, such as a horn switch or a computer as in a power train control module. This p roduces a retarding effect on motion of the rotor in either di rection. /Producer (�� w k h t m l t o p d f) /Type /XObject /Height 16 PDF | On Apr 19, 2016, Vladimir Gurevich published Electric Relays: Principles and Applications | Find, read and cite all the research you need on ResearchGate /Height 2471 Protective Relays Introduction Protective Relaying is one of the several features of the power system design. They are used in various circuits and many of us have problem of how to use a relay. /Subtype /Image >> Relay is a JavaScript framework for building data-driven React applications powered by GraphQL, designed from the ground up to be easy to use, extensible and, most of all, performant. Part 1 Introduction. October 2, 2014 By Anjali Sethiya . <>stream - A relay so designed that a bar actuates several contacts simultaneously. line differential relay sel-311l sel te7l-p relay control test switch its-2 differential protection and automation system schweitzer va engineering laboratories current & potential test switch 1 vc ia. stream 2. a tree branch short-circuiting a power line) and then automatically re-close the breaker to test whether or not the fault has cleared. Introduction of static relays began in the early 1960’s. The relay is a well known and widely used component Applications range from classic panel built control systems to modem interfaces between control microprocessors and their power circuits or any application where reliable galvanic separation is … In a protection relay, the term ‘static’ refers to the absence of moving parts to create the relay characteristic. - A relay in which the characteristics are modified by the introduction of some quantity other than the actuating quantity, and which is usually in opposition to the actuating quantity. relays. /Length 13 0 R /Type /ExtGState stream With the help of this article I have tried to explain two things. e7tip relay control test sel- 387a . Electric power is available to the user These are operated to open or close the load contacts in response to one or more electrical quantities like voltage and current. The TR (transmit-receive) relays in our ham radio transceivers are examples of devices ROTARY SWITCHES TOGGLE SWITCHES SLIDE that are controlled by the circuit within the transceiver. A relay that functions to prevent overheating of the field excitation winding by reducing or interrupting the excitation of the shunt field. Relay is a very important device now days. A relay comprises of an electromagnet and a contact unit. x���_d�#��P�(ъ�Z�WL!��P�~���T���!��ވO�� �^�Kendstream 7 0 obj /SM 0.02 /Subtype /Image INTRODUCTION TO PROTECTIVE RELAYING. 1.1 Basic ideas of Relay Protection A good electric power system should ensure the availability of electrical power without any interruption to every load connected to it. /Filter /FlateDecode << /Type /XObject We know that most of the high end industrial application devices have relays for their effective working. %PDF-1.4 /Width 16 The definition is: Activating the contact unit using electromagnetic attraction, which is produced when electric current exceeding the specified value flows to the electromagnet; the voltage and current (input signal) applied to the coil opens or shuts the contact. Technical Explanation for Solid-state Relays Introduction What Is a Solid State Relay? endobj stream The relay is an automatic protective and switching device which is capable of sensing abnormal conditions in electrical circuits. Introduction to DHCP Relay. 4. Relay Seminar Report with PPT and PDF Free Download: An electrical switch which uses an electromagnet to move a switch from off position to on position instead of using a person to move switch is called as a relay.Very less amount of power is utilized in turning on a relay and it also has the ability to control something which draws a huge amount of power. - Contacts which interrupt one circuit before P. GOPALA KRISHNA ADE/400KV/APTRANSCO Power Systems Protection -Introduction Power Systems FUNCTION OF PROTECTIVE RELAYING. 9 0 obj Relay accomplishes this with static queries and ahead-of-time code generation. Distance relays have a settable maximum torque angle (mta), which is the angle of the current compared to the angle of the voltage at which the relay is most sensitive. In order to understand the function of protective relaying systems, one must be familiar with the nature and the modes of operation of an electric power system. The idea behind frame relay is that you have a single infrastructure from the service provider and multiple customers are connected to it, effectively sharing everything. /Length 9 0 R /Height 2471 D-c offset, effect on induction relays, 32, 39 overreach of distance relays, 82, 350 overreach of overcurrent relays, 308 time constant, 279 D-c relays, single-quantity, 22 directional, 24, 49 Differential relays, 63 see also Percentagedifferential relays Directional-comparison relaying, for bus protection, 277 principle of operation, 106 3 0 obj View INTRODUCTION TO POWER SYSTEM PROTECTION & RELAYS PPT.pdf from EEE 56 at JNTU College of Engineering. Relays are A DHCP relay agent is a host that forwards DHCP packets between clients and servers that do not reside on a shared physical subnet. React allows views to be defined as components where every component is responsible for rendering a part … A Relay comprises of an electromagnet and a contact unit. 14 0 obj relay to provide magnetism in the zero current position. NC = Normally Closed, COM is connected to this when the relay coil is off. /SMask 6 0 R %PDF-1.4 %���� /Filter /FlateDecode 9629 Relay is an switch, which opens and closes the circuit electronically. These relays can work with both AC and DC supply and attract a metal bar or a piece of metal when power is supplied to the coil. /Type /XObject In terms of operation, SSRs are not very different fr om mechanical relays that have moving contacts. [�212��~��Y >$�8tz;QtL�wX����‚}TQ��8�.��J�R�=����r�^,~�I�ֱ�옣����x��(6k�����/�͐�l�Q����Òj`Nd��^��4�6�J1���С��:S�b{�.�6ć���,h+�����+k�6ɴA�,��z��M��R>�.V���?HU�C���A�U���sC'�M@y��D`G�(dX�6�S�0��_9�t��3MOs����ڪ�\�녣e <>/Contents 2 0 R >>endobj Working of relay. /SA true /SMask /None>> /BitsPerComponent 8 12 0 obj INTRODUCTION TO AUTOMATION SYSTEM SARIATI Page 9 The relay's switch connections are usually labelled COM, NC and NO: COM = Common, always connect to this, it is the moving part of the switch. /Width 1971 1. >> This is a picture of frame relay and it works a bit different. PROTECTIVE RELAYING. /SMask 12 0 R /BitsPerComponent 8 /Length 7 0 R /Creator (��) The relay logic control works efficiently to perform basic ON/OFF operations by opening or closing the relay contacts but it involves a humongous wiring. It uses electromagnetism from small voltage to provide higher voltages. /ColorSpace /DeviceRGB >> Reed relays contain a reed switch, a coil for creating a magnetic field, an optional diode for handling back EMF from the coil, a package and a method of connecting to the reed switch and the coil to outside of the package. Relay technology. B3�y&3�?澮�~�������g�?23333333333+�pkmk��;KW����������� endobj Introduction to protective relaying 1.1 What is relaying? Introduction to Relay. /Subtype /Image Some are called VOX (voice- operated) relays because they actuate when we speak into the microphone. Based on operation mechanism protection relay can be categorized as electromagnetic relay, static relay and mechanical relay. The circuit incorporates relays along with other components such as switches, motors, timers, actuators, contactors etc. v�z4�,W��vWg����Y?�*$�m-� ��R}q3$!8{��6�!��N~�܁�V=���+V�%!�I�m�G�Ƒ�Sۙ�� a��%spM�Ru�b�-����ݠ���?�X1�V%ƕ�?�q�����QGUj�n�`�0}]?o�N��6���Ԣ;N��0�$��U�@�fEPq��{U���PYkӒ.���\L-�&(�.��r�+����*�ٷ�9_�H�Ee�' GA�Y_���M�� % �R�U����z%Z�^�+W����J � �;+Z�G�>�ژ_"�ƅ��vp�;ʹ���3�|m�K~8�gE$��w0U�ޠߒQS�^��������]k,,~OcK�G���K`;O`%�՚�?1g9�T\��O�n�̀���^��#��j]��Y�+�P�Ppt����a)~%�Y-Z�(`��Lp�~�!�nA[�����%P�`�`��$����S���f����H��^V��0�"ܩ��L� When we endobj (IA/ICTL/IAC) [60] field relay (power system device function numbers) A relay that functions on a given or abnormally low value or failure of machine field current, or on an excessive value NO = Normally Open, COM is connected to this when the relay coil is on. �l (P6 $( � ��e@�� A� ��l HP6 $( � ��e@�� A� ��l HP6 $( � ��e@�� A� ��l HP6 $( � ��e@�� A� ��l HP6 $( � ��e@�� A� ��l HP6 $( � ��e@�� A� ��l HP6 $( � ��e@�� A� ��l HP6 $( � ��e@�� A� 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[/Pattern /DeviceRGB] /CA 1.0 RELAYING PRINCIPLES. This can be a plunger being drawn towards the solenoid or an armature being attracted towards the poles of an electromagnet, as shown in the figure. x�k�� �m@��q��4� ����endstream A Solid State Relay (SSR) is a re lay that does not have a moving contact. In the drawing on the right, the mta is approximately 75 degrees. 28 Biased relay. Relays allow a small current /ca 1.0 Protective relay Wikipedia (PDF) Protective Relays Mohamed Mashooth Academia.edu. /Filter /FlateDecode << >> 6 0 obj Electric energy is one of the fundamental resources of modern industrial society. /Height 16 Types of protection relays are mainly based on their characteristic, logic, on actuating parameter and operation mechanism. Their design is based on the use of analogue electronic devices instead of coils and magnets to create the relay … /BitsPerComponent 8 Actually, a relay is nothing but a combination of one or more open or closed contacts. Abnormal Operation - Electrical equipment … Relay logic basically consists of relays wired up in a particular fashion to perform the desired switching operations. This icon is the frame relay switch. The relay on the right (just above the “Reclose Cutout” switch) is a reclosing relay, designed to automatically trip the circuit breaker in the event of an instantaneous overcurrent event (e.g. /ColorSpace /DeviceGray the relay to switch on or off automatically. An introduction to Reed Relay basics (Part 1): Reed Relay Basics. When input voltage is applied across its coil, NC changes to NO and NO changes to NC. Relays are used in a wide variety of applications like electric power systems, home appliances, automobiles, industrial equipments, digital computers, etc. stream 3 Frame Relay 3.0.1 Introduction Frame Relay is a high-performance WAN protocol that operates at the physical and Data Link layers of the OSI reference model. The definition is: Activating the contact unit using electromagnetic attraction, which is produced when electric current exceeding the specified value flows to the electromagnet; the voltage and current (input signal) applied to the coil opens or shuts the contact. 1 0 obj /ColorSpace /DeviceRGB Introduction to Relays. SSRs, however, employ semiconductor switching elements, such as thyristors, x��� ���H��dBP��m%�6 �q. /CreationDate (D:20140305093158Z) NO (Normally Open) and NC (Normally Closed). /BitsPerComponent 8 It has two basic contacts i.e. Introduction and Architecture of Numerical Relay April 25, 2018 September 29, 2016 by admin Most of us are aware of Electromagnetic Relays and Static Relays but most us may not be well acquainted with Numerical Relay. Eric Scace, an engineer at Sprint International, invented Frame Relay as a simpler version of the X.25 protocol to use across Integrated Services Digital Network (ISDN) interfaces. 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