3 Zone Protection Using Distance Relays

The protection zone must be configured so as to ensure the safety distance, which has been calculated according to the laws, regulations, and standards of the country or region in which the laser scanner (SZ) is installed as well as according to the specifications given in this document. 01 second at three times the setting can be obtained. Consequently, a total clearance time of around 27 cycles is possible for some faults. Expanded ZSI with network communications. Similarly, if it receives 'start' for 1-phase fault immediately followed by multi- phase fault the later one. Protection Relays by Range. The implementation of distance relays requires understanding of its operating principles,. More specifically, the relay operates depending upon the impedance between the point of fault and the point where relay is installed. Basically distance relay is measure of change in impedance value in between transmission line without fault and transmission line with fault. reach and time settings for a 3-zone distance relay protection are presented in Figure 6. Line Current Differential Relay with integral four zone distance backup for easy-to-apply, high-speed line protection. During internal Zone 2 fault conditions, the relays should detect the fault, issue a trip key command to the relay at the opposite end of the line, and assert its own zone 2 element. CHAPTER 3 A NEW DIRECTIONAL OVER CURRENT RELAYING SCHEME FOR DISTRIBUTION FEEDERS IN THE PRESENCE OF DG 3. re: distance and differential protection 12/03/2009 4:49 PM I agree, you can also use differential protection to protect short overhead lines and it is usually the main type of cable feeder protection using relays such as solkor and translay in conjunction with pilot wires. •A fault within the given zone should cause the tripping of all circuit breakers within that zone and no tripping of breakers outside that zone. Circuit Breaker Problems. In many ways pilot protection is analogous to differential protection of buses , transformers and machines. Frequently asked questions about the safety of radiofrequency (RF) and microwave emissions from transmitters and facilities regulated by the FCC For further information contact the FCC's RF Safety Program at [email protected] But the relay at N can also provide this back-up by reversing the zone 3. The value can be displayed and used to determine the fault location. If it's just a switch then no problem. This method involves the use of a relay in which there is a definite time delay between the moment when the relay is required to operate and the moment when the operation of the relay is completed. ü Generates the set points of Zone 6 and Zone 7 associated to OOS protection ü Set the relay logic to block distance protection longer than the OOS tripping delay • Overload protection "Summer" and "winter" settings account for the variation of rated circuit capacity with ambient temperature and is applied in the line protection. The proposed scheme envisages use of reverse zone of existing numerical distance protection relays in a different way than conventionally used in utilities. A CT is mounted on the earthing. , the protection zone is not exact. The provision shall also be available to enable / disable the zone 2 and zone 3 individually as per requirement by user. to read real time voltage and current signals and to generate Zone 2: this is set to protect 100% of the line length AB, plus at least 50% of the numerical three stepped shortest. In these instances the best choice of protection is current differential protection. the miscoordination of Zone-2 protection can occur in the distance relays. PMU measurements from both ends of line are going to be available. The relay characteristic is illustrated in Fig. Distance protection calculation formulas and procedures 1. A digital relay processes the data using algorithms such as for over-current protection and for distance protection. Figure E-1. aren't include 21 functionality ( I told about EM relays). or microprocessor-based protection relays. Type 3 SPD. Using these units the relay zone boundaries may be tested and the trip time of each zone ascertained. over voltage +time delay 5. For proper protection, proper co-ordination of relays with appropriate relay settings is to be done. Figure 1 presents a comparison of a hidden failure and a non-hidden failure for a three zone step distance relay that was presented in []. For example: 3 - SR735 (or F-30) Main-Tie-Main relays coordinated by a 9030 PLC may be more cost effective than 3-SR 750 relays, depending on the complexity of the throw over scheme. System Characteristics The EHV transmission lines in India are transposed. The relay located at bus 1. The last video in our end-to-end testing series gave you a general overview of distance protection, and why we use it in modern electrical systems. When a fault occurs between one phase and the ground will the fault current travel back from the ground through the neutral to the fault point. An enhanced zone 3 algorithm of a distance relay using transient components and state diagram Abstract: Zone 3 of a distance relay is used to provide the remote backup protection in case of the failure of the primary protection. There are many misconceptions regarding wind energy. Can I use Class PS CT for OC or SEF protection or for metering purpose. This device is imperative when you are using a pump to supply water to your irrigation system. Remote, long distance and low voltage manual control applications, etc. These coefficients are calculated in phasor data concentrator (PDC) at system protection center (SPC) using the magnitude of current phasors obtained from PMUs. The relay will measure the voltage and current, then calculate the impedance (by dividing voltage by current). Led Light Strips For Cars Exterior Dodge Durango Accessories We handpick premium Dodge Durango accessories and parts from the world’s most experienced manufacturers so that we c. , the protection zone is not exact. Use magnitudes from the phase A components. Moreover, since the relays require only current as the operating parameter, their settings can be determined easily. Evaluation of Interstate Work Zone Mobility Using Probe Vehicle Data and Machine Learning Techniques. The feeder protection, if of the unit type, would not operate, since the fault is outside its zone. Single-function and Specialty Relays. The proposed scheme envisages use of reverse zone of existing numerical distance protection relays in a different way than conventionally used in utilities. Authors have proposed a protection scheme using digital relays with communicated network for the micro grid [13]. frequency on the distance-protection performance is analysed in [7]. explain what is meant by 3 zone protection. Relay Receiving Positions – In the 4x400m relay, 3 rd & 4 th runners are placed in the order of their incoming teammates as they complete 200m; after that they will not change positions. DC output. Teaching Distance Relay using Matlab/Simulink Graphical user Interface @inproceedings{Idris2013TeachingDR, title={Teaching Distance Relay using Matlab/Simulink Graphical user Interface}, author={Muhd Hafizi Idris and Surya Hardi and Mohd Zamri Hasan}, year={2013} }. • Built-in interface with relay test set • Intelligent protection zone selection and viewer StarView Toolbar Protective Device Handling • High impedance & percentage differential relay (87) • Phase, ground, & directional overcurrent relay (51/50, 67) • Detailed implementation of voltage restraint & control relay (51V). The distance protection is high speed protection and is simple to apply. 8 Transmission Line Protection Principles 3. As discussed in my earlier post on Distance Protection Philosophy, Zone-1 setting is kept at 80% of the total impedance of the Protected Line. In addition to the above engine that is not compatible with this assembly would be the Gen 3 Chevy engines. Therefore the fault locator is an integral part of the distance protection function. from all the sensors of the protection zone. current source at the local substation, St. In the case of zero fault resistance, the measured impedance by distance relay is the exact impedance of the line section between the fault and the relaying points. Optional 1/3-pole or 3-pole circuit-breaker failure protection using the integrated disconnector image for tripping all circuit breakers of the busbar section affected. 3 Relay A Zone 1 BC-G fault 86 3. DISTANCE PROTECTION SCHEMES Without a suitable protection signalling scheme. 0 International Public License Last update = 20 May 2019. Both relays see a loss of. Similar to the directional Overcurrent relays, the pickup, maximum torque angle, clutch pressure, and contact gap test should be made. If it's just a switch then no problem. Understanding Distance Protection & distance protection relay Why Distance Protection > Since the impedance of a transmission line is proportional to its length, for distance measurement it is appropriate to use a relay capable of measuring the impedance. GE Multilin Application Advantages Before considering using a GE Multilin relay for a specific transmission line protection application, it is important to understand how the relay meets some more general application requirements for simplicity, security, and dependability. , the protection zone is not exact. INTRODUCTION A bus differential protection is applied for protection. The zone 3 Branch breaker does not get a ZSI input signal because it is the last breaker in the distribution network. Zone Protection System of Transmission Line by Distance Relay using Matlab/Simulink Abstract: This work represented the problems on transmission line in different type of zones. Consequently, a total clearance time of around 27 cycles is possible for some faults. distance relays, generator protection relays, and underfrequency load shedding relays. The use of channel to compare conditions at the terminals of a power line, provides the only selective means of high-speed clearing of end zone faults. Digital Differential Protection of Power Transformer Using Matlab, MATLAB - A Fundamental Tool for Scientific Computing and Engineering Applications - Volume 1, Vasilios N. or microprocessor-based protection relays. of insulation from the wire end. It should be adjusted so that it will be able to operate even for arcing faults at the end of the line. • Microprocessor-based Intertie Protection Relay integrates protection, metering, monitoring and waveform capture • Provides 18 base protective relay functions and 3 optional protective functions • Local and remote serial communications capabilities, plus IRIG-B interface Integrated Protection System®. Static Distance Protection Relay are characterized by having two input quantities respectively proportional to the voltage and current at a particular point in the power system, referred to as the relaying point. from all the sensors of the protection zone. NDR processes these inputs and estimates the apparent impedance. protection is the practice of using CTs located in Zone A to provide current inputs to relays protecting Zone B and vice versa, as represented in. ict in Distance Relay OR Trip Main - 1 DR Main - 2 DR OR-logic improves dependability. Zone-1 is normally set to 80% of total length of Line (here line length is AB between two consecutive substation). In Electromagnetic relays operating current flows through the coil. Electrical Engineering. Narendra 1, K. communication process bus. Figure 3 depicts protection zones of distance relays. For a single-pole application, the distance. The Buffalo Bills could use a little better deception and a little more success when it comes to running screen passes. A request to trip is also sent to the relay at end A. Directional comparison Blocking (DCB) allows over reaching relays to trip instantaneously by blocking out of zone faults. How to model a mho distance relay using matlab for transmission line protection? And how to plot the impedance locus on R-X diagram when different faults occur with different fault resistance values and how the relay can be avoided from underreached?. to measure distance east and west map key an explanation of the colors and symbols used on a map metamorphosis a series of changes through which insects go from egg to adult Page 4 Unit 3 Section 1 Lesson 2: Migration Relay Unit 3 Section 1 Lesson 2:. Generally, the current differential relay is used to provide the protection for cables in power systems because it is less affected by the cable characteristics. Phase distance relaying. that the protective relay is a zone 3 relay with a remote backup settings criteria. Zone 2 is set to approximately 50% into the adjacent line, and 25% into the next two lines for Zone 3 as described in [4]. Thus Phase Distance Relays and ground over current relays can provide instantaneous protection for in zone faults. The IDEC SE2L safety laser scanner is the smallest in the world, while outperforming most of the competition. The City of Birmingham is home to 26. This protective func-tion can only be automatically activated if the measuring voltage fails resulting from. therefore we introduce the fault in between this zone. Such relays are employed for restricted earth-fault and other types of circulating current protection. Zone 3 is the backup protection for all the lines connected to the remote end bus. However this is. But the relay at N can also provide this back-up by reversing the zone 3. The control system is comprised of generator voltage. Completed using ETAP 2. The distance protection relays of one of the voltage levels sees always But will the fault impedance be inside of the protection zone?. A mal-operation case of busbar protection caused by a dead-zone protection abnormality in the Brazilian Midwest Grid on September 19th, 2012, is briefly described. The simulation results show that the novel zone 3 distance relay elements using the proposed method operate correctly for various events. frequency on the distance-protection performance is analysed in [7]. Pilot relaying is an adaptation of the principles of differential relaying for the protection of transmission-line sections. tripping - Phase-selective protection of overhead lines and. Very useful explanation Sir. 14) Example 3 Let us calculate the maximum possible distance between the CT and the protection relay with the following. Are you looking to buy a car but can't decide between a Mercedes-Benz C63 or Mercedes-Benz E-Class? Use our side by side comparison to help you make a decision. The operation time for Zone 1 is instantaneous whereas. 3: Fault in the zone of protection (F1) but the guard/trip signal is shorted out by the fault. operation of the relays. The PAZSD methodology employs current coefficients to adjust the zone settings of the distance relays during infeed situations. Distance relays are used for both phase fault and ground fault. Z2 that satisfies both equations 2 and 3 AB o generally set Zone 2 as long as possible. March 1997 3 Overcurrent-time and definite-time overcurrent protection (emergency) The distance protection 7SA511 can be used as a two-stage definite-time over-current protection. therefore we introduce the fault in between this zone. Under Reach of Distance Relay A distance relay is said to under reach when the impedance seen by relay due to fault is more than the relay setting value even though the fault point is within the protected zone of line. Abstract—Widespread use of digital distance relays has increased the application of distance protection to lower voltages,. However, these techniques can also be applied to other load-sensitive phase distance mho-type characteristics. Application of the rated voltage is the most basic requirement for accurate relay operation. " 8 Optically isolated digital status input for monitoring of status and avoid use of external relay logic. Do the Littelfuse Arc-Flash Relays provide zone tripping? AF0500 has two high speed IGBT outputs for tripping of circuit. A typical misapplication is the use of small multipole relays in 112/200 volt 3-phase ac applications. The relay will measure the voltage and current, then calculate the impedance (by dividing voltage by current). •Zone 1 under-reaching distance element, TD21 No communications required •POTT Scheme using TD32 and TW32 PLC, SONET, Direct fiber •TW based differential element, TW87 Direct fiber, Dense wavelength division multiplexing networks Time Domain Protection Elements/Schemes Delivers Speed with Security. Although the performance of reactance relays on single-fed systems is not unduly affected by fault resistance, there may be occasions in double-fed systems where. The proposed power swing identification algorithm for Zone 3 distance relays blocking is simple, involves only a few calculation steps, and can be applied to any power system configuration. Zones of Protection. With their flexibility and the high-performance DIGSI 5 engineering tool, the SIPROTEC 5 devices offer future-oriented system solutions with high investment security and low operating costs. Therefore, to set zone-3 the settings of zone-2 of the relay and the longest adjacent line are needed. The operation of the conventional over current relays either direction or non directional, depend on the magnitude of current or power in the protected circuit, where as the distance protection relay operate on the principle of the ratio of applied voltage to current in that circuit. Application - Line protection for all voltage levels with 3-pole. lengths with up to. It can be used in Carrier Aided Distance Scheme and Autoreclosing Scheme. scheme', or ‘intertripping under-reach distance protection scheme’, as the Zone 1 relay elements do not cover the whole of the line. Dual distance protection algorithms The operation of the MiCOM relays is based on the combined. The functioning of the distance relays during infeed condition with and without the pro-. txt) or view presentation slides online. As relay diagrams show, when a relay contact is normally open (NO), there is an open contact when the relay is not energized. There is one type of relay which functions depending upon the distance of fault in the line. If the estimated impedance is within the set zone of protection, tripping signal is. instantaneous, under-reaching step distance relays (generally zone 1). DC output. A wide‐area backup protection (WABP) method is proposed in this paper based on the zone status of distance relays. Basic concept of communication assisted protection. Figure E-1 - Overlapping zones of protection. or microprocessor-based protection relays. different protection zones of the distance relay units. Three stepped Distance-relay protection zones Zone 1: this is set to protect between 80% of the line length AB. 8 Transmission Line Protection Principles 3. Use the GND terminals as common terminals for the zones. This rule is most appropriate for many reasons, the most important being the lack of overlap between two or more relays in the same protection zone. Up to age 10 and/or a minimum height of 140cm, children must use a size-appropriate type of front-facing child seat or booster. time delay and send a zone output signal to the protective relay EDR-5000 in zone 1. The fault impedance is calculated by the distance protection. The use of phase comparators in the classical approach compared compensated voltage (V-IZ) with the polarizing voltage VP, where V and I are fault voltages and currents, respectively. 3 Relay A Zone 1 BC-G fault 86 3. Ideally, impedance is perfectly proportional along the line. Overlapping zones ensure that equipment located at the edges of a zone is protected. Relay MIRRORED BITS Communications Relay ® Program pushbuttons to activate instantaneous maintenance settings. Zone coordination Subsystem 2. Our course begins with the first step for generating great user experiences: understanding what people do, think, say, and feel. txt) or view presentation slides online. This paper presents both the analytical and. frequency on the distance-protection performance is analysed in [7]. •Zone 1 under-reaching distance element, TD21 No communications required •POTT Scheme using TD32 and TW32 PLC, SONET, Direct fiber •TW based differential element, TW87 Direct fiber, Dense wavelength division multiplexing networks Time Domain Protection Elements/Schemes Delivers Speed with Security. distance relays have been used widely replacing the electromechanical and static distance relays. Relay settings are done in such a way that proper co-ordination is achieved along various series network. • Area protection with 2, 3 or 4 beams • Sensing distance 10 m • Space saving M18 housing brass and plastic types are available • Complies with EN 61496-1 Type 2 (with controller F3SP-U1P-TGR) • Multifunctional controller for up to 4 sensors with integrated muting • Accessories: cables, mirrors. 13 Distance Relay Applications for Tapped and Multiterminal Lines; 12. Tutorial on Distance and Over Current Protection Zone 3 •ALL is 200 km to Berhampore •X3_Prim = 0. reach and time settings for a 3-zone distance relay protection are presented in Figure 6. The coordination is achieved by providing sufficient time delays between the operations of primary and backup relays. Zone 2/3 of Distance Protection g. Similarly, if it receives 'start' for 1-phase fault immediately followed by multi- phase fault the later one. Distance elements enhance selectivity further by being both directional and having a defined reach in terms of impedance. Type 2 SPD is characterized by an 8/20 µs current wave. 1(a) results in operation of the Zone 1 relay and tripping of the circuit breaker at end B. 3 2008, c TUB¨ ˙ITAK Distance Relaying Algorithm for Double-Circuit Transmission Line with Compensation for Reactance Effect under Standard Availability of Measurements Jan IZYKOWSKI, Marcin BOZEK Wroclaw University of Technology Institute of Electrical Power Engineering Wybrzeze Wyspianskiego 27 50-370 Wroclaw. Distance Protection ; Thermal overload protection (Use for underground power system) We are plan to discuss more about this transmission line protection systems in our future articles separately. • Microprocessor-based Intertie Protection Relay integrates protection, metering, monitoring and waveform capture • Provides 18 base protective relay functions and 3 optional protective functions • Local and remote serial communications capabilities, plus IRIG-B interface Integrated Protection System®. In Zone of Protection, Careful selection of the reach point settings and tripping times for various zones of measurement enables correct coordination between distance relays on a power system. This type of relaying provides protection against any type of phase fault. Principles of Differential Relaying The Restraint Characteristic What needs to be realised is that the first one is properly termed the restraint characteristic (RC) whilst the latter is an operating characteristic. The space required for strollers and wheelchairs is about 3. The coordination is achieved by providing sufficient time delays between the operations of primary and backup relays. Perera 1, K. The operation process of pilot distance, automatic re-closure, busbar differential and dead-zone protection, and the emphasis on the logic scheme of dead-zone protection are analyzed. distance protect. Datasheet SAFESERIES SIL RELAYS SCS Series NEW Weidmuller, Canada safety relay is intended for use in back-up Creepage and clearance distance input – output. The line on the right is protected with two distance protection re-lays (SN100). frequency on the distance-protection performance is analysed in [7]. Each zone shall be individually settable for its R and X values. In testing distance relays, the 50A-3PH acts as a simple current source, supplying 3 phase current to the relay under test and a phase reference to the DVS3. A mal-operation case of busbar protection caused by a dead-zone protection abnormality in the Brazilian Midwest Grid on September 19th, 2012, is briefly described. It should be adjusted so that it will be able to operate even for arcing faults at the end of the line. In this manner the relay operation and restoration timing are easily synchronized with the power source frequency, and the timing of the load switching also is easily synchronized. In [7], a line-protection criterion is formed according to the phase difference between the voltage at the fault point and the compensatory voltage in the in-zone and out-of-zone faults. PMU measurements from both ends of line are going to be available. TECH EEE, SHADAN COLLEGE OF ENGINEERING & TECHNOLOGY. Midence , A. Introduction Zone 3 of a distance relay is traditionally used to. fl ABB Relays Type RAZFE B03-7014E Three-zone. understand the concept of different types of relays, including differential relay, ohm relay, mho relay, directional relay, distance relay, relay etc and their reactance. For each component of the protection zone, the Quadratized Dynamic Model (QDM) is developed. , due to differences in power supply type, voltage fluctuations, and rises in temperature. Zone 3 settings • Time delay > Remote Zone 2 (say 50msec pickup + 300msec time delay) + remote CB (say 80msec) + remote trip relay (say 10msec) + local Zone 3 timing errors (say 50msec) + safety margin (say 50 to 100msec). Distance relay will be designed to protect the power system by using some logic from the observed waveforms. The ground relay zone of protection can be defined as a current threshold or measured impedance. March 1997 3 Overcurrent-time and definite-time overcurrent protection (emergency) The distance protection 7SA511 can be used as a two-stage definite-time over-current protection. What this means is the relay will prevent someone from attempting too many successive re-starts of a large. Controlled reach t is tha independent from system and fault conditions lays a foundation for the application of a distance element for tripping line faults directly without a pilot channel ("Zone 1"). Protection of Bus bars – Differential protection. Protection requirement LV MV 70kV…150kV 275kV…500kV Fuse, MCB Overcurrent relays - Main prot - Backup prot - Main 1 - Main 2 Shorter operating time Protection application System topology and characteristic Protection zones, Fault detection, Suitable protection scheme and algorithm Protection relay selection & settings Higher CT requirement. between the main and the backup relay [3-5]. If you are not sure exactly where the pickup value of the relay is, you can use the Pulse Ramp Binary Search feature. Timing Test Feature. Support Vector Machines (SVMs), a class of patterns classifiers are used in discriminating zone settings (Zone-1, Zone-2 and Zone-3) using the signals to be. scheme', or ‘intertripping under-reach distance protection scheme’, as the Zone 1 relay elements do not cover the whole of the line. Principles and Characteristics of Distance Protection These relays may sometimes be set based in percentages of the line impedances, for example a typical setting for zone 1 is 80% of the impedance of the line in order to not reach the remote end, the zone 2 can be set at 120% of the impedance of the line in order to dependably overreach the. reach and time settings for a 3-zone distance relay protection are presented in Figure 6. REF protection is based on the fundamental current, after filtering. If it's just a switch then no problem. Also differential protection scheme. In order to provide an effective network protection to meshed micro grid multilevel approach is adopted in paper [14]. Principle of Distance Protection The term distance is used for a family of relays that respond to a ratio of voltage to current and therefore to impedance or component of impedance. A CT is mounted on the earthing. 0, new settings importers for XRIO file types are provided. The purpose of this. These models adequately represent distance relay. Characters present in TNT's series The Last Ship. 3 Create the faults and observe whether relays 3. lockout relays (86) to help ensure that protection is available even with a failure of one 86 relay or its dc feed. Therefore the fault locator is an integral part of the distance protection function. A Reverse Zone 4 is used in pilot schemes and/or as a backup zone for bus faults behind the relay. In radial feeder, the power flows in one direction only, which is from source to load. TRANSFORMER DIFFERENTIAL PROTECTION Percentage restraint differential protective relays have. Models available: MiCOM P120, MiCOM P121, MiCOM P122, MiCOM P123, MiCOM P125, MiCOM P126, MiCOM P127. (a) Reach of a distance relay (b) Under reach of a distance relay 18. scheme', or 'intertripping under-reach distance protection scheme', as the Zone 1 relay elements do not cover the whole of the line. In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker when a fault is detected. Completed using ETAP 2. Distance protection is and remains by far the main protection principle for overhead lines and cables. T 3 = Time delay setting for the operation of the zone 3 element of distance relay. Technical Publications, Carrier current and three-zone distance relay protection using impedance relays. The SIPROTEC 7SA82/86/87 distance protection have been designed particularly for the protection of lines in medium-voltage and high-voltage systems. Circuit Breaker Problems. The Bills have thrown 16. Understanding Distance Protection & distance protection relay Why Distance Protection > Since the impedance of a transmission line is proportional to its length, for distance measurement it is appropriate to use a relay capable of measuring the impedance. Static Distance Protection Relay:. However, due to the simplicity of line differential schemes, there has been an increase in the use of differential relays for complex networks. Midence , A. Actually, all modern mho impedance relays for phase, ground and 3-phase protection have an expanded characteristic that includes the origin. The defense even managed to keep LSU out of the end zone for a full quarter—the first—which had not been done by any opponent all season. In Electromagnetic relays operating current flows through the coil. The PAZSD methodology employs current coefficients to adjust the zone settings of the distance relays during infeed situations. Timing Test Feature. DISTANCE PROTECTION SCHEMES Without a suitable protection signalling scheme. Switchgear And Protection. However the DFROBOT relay shield can be configured to use any Arduino digital output to drive the. It is a voltage controlled equipment. Static Distance Protection Relay are characterized by having two input quantities respectively proportional to the voltage and current at a particular point in the power system, referred to as the relaying point. Zone 2/3 of Distance Protection g. A wide‐area backup protection (WABP) method is proposed in this paper based on the zone status of distance relays. The defense even managed to keep LSU out of the end zone for a full quarter—the first—which had not been done by any opponent all season. Relay co-ordination can be done by selecting proper plug setting and. Also differential protection scheme. Power System Protection Applications and Performance Analysis. Also, transformers and compensation coils within the differential protection zone are protected as are serial and parallel-compensated lines and cables. This paper presents a new method to prevent cascaded events caused by zone 3 elements of distance relays due to transmission line overload by using logic controls. validate the present method, the performance of developed distance relay is tested using the data generated by Simulink/MATLAB simulator. relay single measuring system distance zone select. instantaneous, under-reaching step distance relays (generally zone 1). A block diagram of a distance relay based on current comparison principle is given in Fig. These coefficients are calculated in phasor data concentrator (PDC) at system protection center (SPC) using the magnitude of current phasors obtained from PMUs. shorting switch at rear of the panel. In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker when a fault is detected. UNIT – VI Feeder and Bus-Bar Protection. The relay characteristic is illustrated in Fig. The basic principle of distance relay is that the apparent impedance seen by the relay, which is defined as the ratio of phase voltage to line current of a transmission. In distance protection Characteristics are also different for both primary & backup relays. A Reverse Zone 4 is used in pilot schemes and/or as a backup zone for bus faults behind the relay. Pumps are built to use normal house currents; the relay changes the irrigation timer to normal household voltage. Basic principles Characteristics and operating principles of Mho Characteristics and operating principles of Quad Polarization for phase and ground distance Determination of directionality. With an instantaneous zone 1 protection that covers 80-90% of the transmission line and subsequent time delayed, and coordinated zone 2 and zone 3 protection, a distance relay has been able to win the hearts of protection engineers over the years. A lack of trip signal from the CB2 relay prevents the CB1 relay from tripping. Performed NERC based relay load limit study to find over-reaching zone 3 distance relays. When a fault is detected, the relay trips a circuit breaker and triggers an alarm signal that could be communicated, for example, to a display terminal via a RS232 line as shown below. Apply subcycle current differential protection with included four More information. The operation of the conventional over current relays either direction or non directional, depend on the magnitude of current or power in the protected circuit, where as the distance protection relay operate on the principle of the ratio of applied voltage to current in that circuit. Q ast three single line diagrams of power system network where Directional 2. operation of the relays. frequency on the distance-protection performance is analysed in [7]. 33 shows a three-zone step distance relaying scheme that provides instantaneous protection over 80-90% of the protected line section (Zone 1) and time-delayed protection over the remainder of the line (Zone 2) plus backup protection over the adjacent line section. Transmission Line Protection Setting Calculation Phase Distance Pilot Tripping Zone Number of relay elements is limited Step Zone 2 or Step Zone 3 can be reused. Distance protection is non-unit type protection, the protection zone is not exact. Circuit Breaker • Back-up Protection Back-up protection is the name given to a protection which backs the primary protection whenever the later fails in operation. • Microprocessor-based Intertie Protection Relay integrates protection, metering, monitoring and waveform capture • Provides 18 base protective relay functions and 3 optional protective functions • Local and remote serial communications capabilities, plus IRIG-B interface Integrated Protection System®. Letters are sometimes added to specify the application (IEEE Standard C37. REF protection is based on the fundamental current, after filtering. between distance relays on a power system. 13 Distance Relay Applications for Tapped and Multiterminal Lines; 12. Therefore, to set zone-3 the settings of zone-2 of the relay and the longest adjacent line are needed. In addition models P442 and P444 allow single-phase tripping for the distance protection and the channel-aided DEF protection. In this case, the extreme load pattern 28 (forward), shown by dotted lines, encroaches upon two zones. what is the distance protection philosophy? How many zones are there? Can you discuss the characteristic of the zone? How can you plot it on the paper?. The distance protection relays of one of the voltage levels sees always But will the fault impedance be inside of the protection zone?. lockout relays (86) to help ensure that protection is available even with a failure of one 86 relay or its dc feed. A method for determining the trip characteristics of distance relays, especially having protection zone switching, for protection of an electrical line by means of variable comparison impedances, wherein the distance relay has a measuring element employed as a comparison instrument, comprising the steps of:. different protection zones of the distance relay units. The RAZOA distance has been taken for line protection and REL-100 a non-switched. DISTANCE RELAYS FUNDAMENTALS J. 3 Zone Protection Coordination Careful selection of the reach settings and tripping times for the various zones of measurement enables correct coordination between distance relays on a power system. It provides instantaneous tripping for all combinations of phase-to-phase faults, two-phase-to-ground faults, and three-phase faults.