This impedance or corresponding distance is called the reach of relay. A new technique for setting calculation of digital distance relays. Pierz abstracta group of the algorithms aimed at measuring a faultloop impedance for digital distance relay has been. Observe that for the balance point fault, the v is exactly equal to iz. Numerical distance protection relay commissioning and testing. Instead of using analog signals, the digital relay converts all measured analog quantities into digital signals. Pdf this paper describes modelling and testing of a digital distance relay for transmission line protection using matlabsimulink. Development of distance relay models for real time digital simulator. Compared to the solid state relay, the digital relay takes the advantages of the development of microprocessors and microcontrollers.
Typical reach and time settings for a 3zone distance protection are shown in figure 11. Protective relay testing using a modern digital real time. This impedance between the relay and the fault depends on the electrical distance between them. Since type testing of a digital or numerical relay involves testing of software as well as hardware. Dynamic phasordriven digital distance relays protection. Variable digital filter response time in a digital distance relay j. Ur relay providing feeder protection and metering for up to 5 breakers with bus monitoring. Simulinks power system blockset psb is used for detailed modelling of a power system network and fault simulation. Power system protection relays can be categorized into different types of relays.
An adaptive digital distance relay for ehv transmission. Protective relay testing using a modern digital real time simulator g. Distance relay or impedance relay working principle types. Common settings for three forwardlooking zones of basic distance relay protection are shown in the following paragraphs.
Since distance relay determines the tripping conditions based on the phase comparison of the operation and polarization voltages, which are calculated. However, for modern digital or numerical distance relays, the variation between these is small over a wide range of system operating conditions. The mho function uses the current and voltage measured at the relay to determine if the apparent impedance plots within the mho characteristic. Digital relay reference guide by keith brock, ge sr.
Then, one has only the problem of adjusting the first and secondzone units. Digital distance relay mitsubishi denki kabushiki kaisha. Some applications also might use a 32 power element, based. The relay is designed to provide fast and selective fault clearance on transmission and subtransmission cables and overhead lines with or without series capacitor compensation.
Revised edition released november 1998 previously presented at the 12th annual cepsi exhibition, november 1998, international conference modern trends in the protection schemes of. A distance relay operates whenever the distance seen by the relay is less than the prespecified impedance. Protective relay testing using a modern digital real time simulator. Sep 01, 2018 there is one type of relay which functions depending upon the distance of fault in the line. Ppt protection and relay schemes powerpoint presentation. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience.
In digital relay on and off state can be referred as 1 and 0 state. Pdf numerical relays are developed due to the advancement in the application of microprocessor technology in relaying industry. There is one type of relay which functions depending upon the distance of fault in the line. Variable digital filter response time in a digital distance relay. Modeling and testing of a digital distance relay matlab. The actuating impedance in the relay is the function of distance in a distance protection relay. Types of electrical protection relays or protective relays. The simulation results shows the impact of statcom on distance relay when statcom is connected at starting end, midpoint and at end side during phase to ground fault condition. Matlab is used to implement programs of digital distance relaying algorithms and to serve as main software environment. Six received in revised form 8 april 2012 different phase to phase and phase to ground measuring units of the distance relay are simulated to accepted 17 may. The present invention relates to digital distance relays, and more specifically to a digital distance relay wherein each of n phases on duty among six phases has distance measuring elements in steps. They are usually slightly slower than some of the older relay designs when. Teaching distance relay using matlabsimulink graphical user. This research article proposes a novel mho relay algorithm to improve the performance of distance relay in presence of facts device using phasor measurement unit pmu.
The functions in the distance relay have a hierarchy that needs to be considered for the testing of the device see figure 1. Basic distance protection will comprise instantaneous directional zone 1 protection and one or more timedelayed zones. Digital and numerical distance relays may have up to five zones, some set to measure in the reverse direction. However, for modern digital or numerical distance relays, the variation between these is small over a wide range of system operating conditions and fault positions. We shall also explain the essentially common features of various digital relaying schemes, other detailed aspects being discussed in later chapters. Digital distance relay reliability enhancement using real. Protect any transmission line using a combination of five zones of phase and grounddistance and directional overcurrent elements. Alexander general electric co malvern, pa introduction distance functions have been in use for many years and have progressed from the original electromechanical types thr ough analog types and now up to digital types of functions. The value of the potential that appears at the fault location during a ground fault at a highvoltage overhead line depends on many different factors and cannot be considered as an a priori known quantity. Alexander general electric co malvern, pa introduction distance functions have been in use for many years and have progressed from the original electromechanical types thr ough analog types and now up. Pdf digital distance relay modeling and testing using labview. Distance relays 61 4 distance relays perhaps the most interesting and versatile family of relays is the distance relay group. 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.
Implementation of a distance relay to protect transmission line l1 3. These relays are known as distance relay or impedance relay. Digital distance protection of transmission lines experience with a. Pdf digital distance protection of transmission lines in the. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. Based on characteristic the protection relay can be categorized as. This paper presents basic distance and directional element design. The siprotec 7sa522 relay provides fullscheme distance protection and incorporates all functions usually required for the protection of a power line. The basic principles of a digital distance relay and some related filtering techniques are also described in this paper.
Implementation of a distance relay to protect transmission. It is now applied extensively in many area of electrical engineering including protective relaying in power systems. Power system, distance relay unit, realtime digital filter, sdft algorithm. Realization of distance relay algorithm using emtp models. A large emphasis is placed on relating the newer digital and numerical methods to the established electromechanical and staticanalog methods of designing relay elements. A simple mho distance function, with a reach of z ohms, is shown in figure 1. The time of operation of such protection is a function of the ratio of voltage and current, i. Alexander protection and control general electric company malvern, pa j. Matlab is used to implement can quickly develop a program of protective relay programs of digital distance relaying algorithms and to serve algorithms, and a. The digital protective relay is a protective relay that uses a microprocessor to analyze power system voltages, currents or other process quantities for the purpose of detection of faults in an electric power system or industrial process system.
In the preceding chapter, we examined relays in which one current was balanced against another current, and we saw that the operating characteristic could be expressed as a ratio of the two currents. Impact of sssc on the digital distance relaying request pdf. This paper describes modelling and testing of a digital distance relay for transmission line protection using matlabsimulink. Analysis of the behavior of one digital distance relay under islanding condition with atp c. Simulinks power system blockset psb is used for detailed modelling. Apply the sel421 for highspeed distance and directional protection and complete control of a twobreaker bay. Relay trip signal from the distance relay 21 to the circuit breaker to protect the transmission line l1 in case of fault rest of the power system figure 4. Distance protection for transmission lines siprotec 7sa522. Since we do not know the fault voltages, we need to take the latter approach, so we can calculate relay voltage from 0, 0, 0, 11, 1, 1, 2, 2, 0000 0 000 relay sys relay, relay sys sys relay relay sys 2, relay vz i vv. Use of advanced digital simulators for distance relay.
Analysis of the behavior of one digital distance relay. A digital protective relay may also be called a numeric protective relay. Pdf modeling and testing of a digital distance relay. More specifically, the relay operates depending upon the impedance between the point of fault and the point where relay is installed. This is true for the threephase fault shown also for a phasetophase fault and for a phase distance function only. Pdf modeling and testing of a digital distance relay using. Sep 26, 1995 a subcycle digital distance relay which uses only the first n2 samples after a fault to calculate the distance to the fault using a full cycle fourier algorithm which operates on n samples, where n is the number of samples taken in a cycle of the power signal. The authors of paper 8 investigate the sssc influence on the performance of digital distance relay in two parallel transmission lines 400 kv. Modeling and testing of a digital distance relay using matlabsimulink. Epac 31003500 numerical distance relay with integrated automatic and control functions 2 features fully numerical distance relay designed to protect overhead lines and underground cables. Relaying is the branch of electric power engineering concerned with the principles of design. Pierz abstracta group of the algorithms aimed at measuring a faultloop impedance for digital distance relay has been considered.
Use of advanced digital simulators for distance relay design and application testing j. Distance relaying scheme for extra high voltage transmission lines, july. Pdf modeling and testing of a digital distance relay matlab. Calzolari abstractdue to a fault in one 150 kv radial transmission network, an isolated network with passive loads and induction motors is developed. Variable digital filter response time in a digital. However, any relay tester can perform successful endtoend tests with a basic a basic understanding of. Thorp cornell university ithaca, ny introduction this paper will investigate the effect of digital filtering on the operating time of a generic digital distance relay.
The other physical quantities like heat temperature etc. Numerical distance protection relay commissioning and testing hung manh tran henry akyea thesis for the degree of master of science, october 2005 department of energy and environment division of electric power engineering chalmers university of technology goteborg, sweden. This diagram is exactly equal to an rx diagram except that all of the impedance vectors have been operated on by the current i. First of all, the secondary currents and voltages that are applied to the distance protection relay are filtered and processed in the analog input module and provide. With their flexibility and the highperformance digsi 5 engineering tool, the siprotec 5 devices offer futureoriented system solutions with high investment security and low operating costs. Jan 04, 2015 endtoend testing can appear to be a daunting task. Owing to this, the influence of this quantity on the current and voltage measured at one of the line terminals is also unknown so the fault distance cannot be exactly calculated, and as a. Digital relays, distance relay model, real time digital simulator, capacitive. Distance relays are designed to respond change in current, voltage, and the phase angle between.
Selection of the protection system for machines and plants. Static relay digital relay numerical relay 1925single disc type relay single input 1963static relay all purpose. Principles and characteristics of distance protection. Adverse effect of fault resistance a digital distance relay uses sampled voltage and current data from the relaying point for measuring the apparent impedance and then uses an appropriate characteristic to make proper decisions to disconnect faulted line. Distance protection siprotec 5 siemens global website. This runs from simple overcurrent and earth fault relays, through to highlevel differential and distance protection schemes. The static relay only gives the response to the electrical signal. The algorithms gathered in two basic families have.
Medium voltage products technical guide protection. Under no circumstances should the reach of any unit be so long that the unit would operate for any load condition or would fail to reset for such a condition if it had previously operated for any reason. Impact analysis of statcom on distance relay open access. In the presence of statcom, its controlling parameters as well as its installation location also affect the tripping characteristic. It is usual for electromechanical and static distance relays to claim both maximum and minimum operating times. They are usually slightly slower than some of the older relay designs when operating under the best conditions, but their maximum operating times are also less under adverse waveform conditions or for boundary fault conditions. Relays respond to one or more electrical quantities like voltage or current such that they open or close the contacts or circuits. Nevertheless, the proposal in this paper lies in the distance relay performance using the taylorkalmanfourier t 2 kf filter, which is analysed as input in a phase comparator in a digital relay. Numerical distance protection relay commissioning and. Experience with a digital distance relay algorithm, which also utilizes a digital low pass filter, is presented. Digital relays sometimes called microprocessorbased or numerical relays can more precisely and economically manage system protection, coordination and communication as compared to traditional analog electricalmechanical relays.
Jun 08, 2019 the actuating impedance in the relay is the function of distance in a distance protection relay. The siprotec 7sa828687 distance protection have been designed particularly for the protection of lines in mediumvoltage and highvoltage systems. Digital and numerical distance protection relays may have up to five or six protection zones, some set to sense in the reverse direction. Distance relay characteristics some numerical relays measure the absolute fault impedance and then determine whether operation is required according to impedance boundaries defined on the rx diagram. Working of relayshow relay works,basics,design,construction. Oct 25, 2005 matlab is used to implement programs of digital distance relaying algorithms and to serve as main software environment. An adaptive digital distance relay for ehv transmission lines.