Benefits or advantages of Solid State Relay. Your email address will not be published. SEL is all numeric relays. (1 relay can be used as over current only for under voltage we use another relay). Loss of voltage feature helps block the relay in case of momentary/permanent loss of voltage. Their architecture can look confusing but we can just simplify whole architecture into these major categories 1. a power switching solution that can be used to allocate power without manually opening and closing the switch Electro Mechanical Relay • Generally Electro-Mechanical Relays are separately used for individual Phases • High Set Setting is having different mechanism • It consumes more space in Panels which increases C&R Panel cost Numerical Relay • All Numerical Relays are compact in size • All Protection functions are available in same relay • The Numerical Relay is 20% in size of Electro-Mechanical Relays … Keywords-Electromechanical relay, numerical relay, Local breaker backup, Bus bar protection, Goose The high powered analog signals are stepped down with current tran… Consists of … The numeric relay can be called as a miniature computer as they both have similar hardware architecture with slight differences. it is having great sensitivity and good pickup ratio. the numerical relay is having very less tripping times compared to mechanical relays. The advantages of solid-state relays include the following: • SSRs are typically smaller than EMRs, conserving Delay in operation: Easily provided and mechanical relay required more electrical wiring but numerical relay required very less wiring. Electromechanical and static relays have fixed wiring and the setting is manual. Which of the following is not an advantage of solid state relays over electromechanical relays. Numerical relays are natural developments of digital relays due to advances in technology. There are no physical moving parts involved in the design of solid state relay. Relays are used to switch starting coils in contactors and motor starters, heating elements, pilot lights, audible alarms, and some small motors (less than 1/8, HP). the numerical relay having system stored  each fault records, types of fault, nature of fault, fault timing, fault present duration, etc.. but the mechanical required each relay for each protection and modification also very difficult. 5. Depending on the function of the relay in the system, either one could prove to be the most desirabe. earlier days we are used mechanical relay and also we used individual relay for each protection of the equipment. can be classified to several types attracted armature moving coil induction thermal advantages of numerical realys flexibility in … the advantages of a modern numerical relay over static relay equivalents. there are different types of relay used in electrical field. the numerical relays are having simple hardware. Electromechanical Relays have traditionally been used in machine tool control, industrial assembly lines, and commercial equipment. The distinction between digital and numerical relays is particular to Protection. Etc. Flexibility. As a safety device, my feeling is that they are less likely to fail closed, where the electronic device can short-circuit. The other physical quantities like heat temperature etc. If you also want to replace Electromechanical Relay with Numerical Relay, mail your  requirement me at BDM@systemprotection.in, Case Study - How we saved a Process Plant…, By combining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays, Separate connection is not required, zero sequence voltages and currents can be derived inside the processor. In a digital/numeric relay, many functions are implemented by the microprocessor programming. the numerical relays are having microprocessor control systems so the heating of equipment is very less compared to mechanical relays. A significant improvement in the relay reliability is obtained because the use of fewer components results in less interconnections and reduced component failures. (1 relay can be used as over current relay, under voltage relay etc.) How Alternator is working? It is smaller in size. The first numerical relays were released in 1985. The following are the benefits of static relays. Users can configure relay according to their system requirement. so it can be easily service. Traditional electromechanical and static protection relays offers single-function and single characteristics. numerical relays relay technology electromechanical relays : mechanical forces causes operation of relay contact in response to a signal. Solid state relays use _____ as switching devices. Relays detect and locate faults by measuring electrical quantities in the power system which are different during normal and intolerable conditions. Memory 4. A variety of protection functions can be accomplished with suitable modifications in … the single numerical relay is having multiple protection systems. Today, we will dive into some of the advantages of PLCs. Output module 6. we will see one by one here. here we will see what are the advantages using numerical relay over mechanical relay. They use one or more digital signal processors (DSP) optimised for real time signal processing, running the mathematical algorithms for the protection functions. CPU 3. There are many advantages that a PLC system holds over a relay system. And relays are less easily damaged by brief shorts or overloads. In the era of electromechanical and solid state relays, any one relay could implement only one or two protective functions, so a complete protection system may have many relays on its panel. This relay directly with numerical. 3. Functions: 1 relay can perform various functions. 4. ... the coil. so what ever the protection system we want to do activate by simply adding software to the system. Electromechanical relays are used in many of today's electrical machines when it is vital to control a circuit, either with a low power signal or when multiple circuits must be controlled by one single signal. but mechanical relay is having single characteristics. In the earlier days, different types of relays are used for the electric protection/controlling system. One relay can be used in many ways. semiconductors. The IEEE defines protective relays as: “relays whose function is to detect defective lines or apparatus or other power system conditions of an abnormal or dangerous nature and to initiate appropriate control circuit action ”. When this operating current increases, coil energizes the electromagnet. but numerical relay is having LCD to indicate the alarm and relay activation. A variety of protection functions can be accomplished with suitable modifications in the software only either with the same hardware or with slight modifications in the hardware. Advantages of Numerical Relays: Numerical relay consists of many functions in one relay thus replace many traditional relays with one. Many electronic designs can take advantage of the improved performance of solid-state relays (SSRs) relative to that of electro-mechanical relays (EMRs) that perform the same circuit function. We know that there are different types of relays available like Over Current relays, Distance relays, and Differential relays, etc. It is possible to provide better matching of protection characteristics since these characteristics are stored in the memory of the microprocessor. Multilin is, I believe, all numeric relays, while some of GE's historic solid state and electro-mechanical relays are still produced. less susceptibility to damage from voltage and current spikes. The disadvantages of a conventional electromechanical relay are overcome by using micro controller for realizing the operation of the relays. They then also have a family of multi-function numeric relays. By combining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays. These relays require to be calibrated periodically and tested. the numerical relay having compact size compared to electro mechanical relays, the electro mechanical relays having lot of components, including flag systems. It is a hardware switching device to control the electrical circuit by using switching logic. Multiplexer and Analog to digital converter 5. Advantages of Numerical relays 1. Flexibility. Electromechanical relays close in 1-3 mSec, and CAN open in < 5mSec. Relay will show automactlly because it was link with history data. Numeric relays, on the other hand, are programmable relays where the characteristics and behavior can be programmed. but now a days the advance numerical relays are coming and single relay having multiple protections. Fibre optical communication with substation LAN. The continuing reduction in the cost and size of microprocessors, memory and I/O circuitry leads to a si… Here, a case study relating to both electromechanical relay and numerical relay will be done and the results are analyzed. In Electromagnetic relays operating current flows through the coil. The microprocessor based relays have minimum burden on the instrument transformers. difference between squirrel cage and slip ring induction motor, What is transistor & How transistor working, Difference between conductor and insulator, How to get pure sinusoidal AC output from DC input using PWM inverter. Advantages of Static Relay. One significant advantage of a solid-state SCR or TRIAC relay over an electromechanical device is its natural tendency to open the AC circuit only at a point of zero load current. Sulphur Hexaflouride (SF6) Circuit Breakers. some of the relay like over voltage, over current protection , under voltage protection, earth fault protection. Auto reset: It has been highlighted, how the numerical relay is flexible according to requirement. By combining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays. the numerical relay is having microprocessor control system so it can be easily adjust the required characteristics needed for the equipments. There are multiple advantages using numerical relays. Different types of relay characteristics. Multi Function Capability. This is help to find natural & duration fault. Reliability. Your email address will not be published. The relay manufacturer's use three groupings: electro-mechanical, static, and numeric. Any one numeric relay may implement one or all of these functions. Application of various relays used in the power system network depends upon various factors like the amount of fault current, protection methods, etc. A relay is an electro-mechanical operator switch. Once you activity relay than you didn’t have to check your electrical machinery. 36 COST OF NUMERICAL RELAYS Modern numerical protection devices have multiple protection elements and this technique makes the cost of the relay comparable with that of electromechanical and static relays … Greater sensitivity and high pickup ratio. It uses a flag system for the indication purpose whether the relay has been activated or not. the numerical relay is having the microprocessor based control systems so it can be easily communicate with computer or laptop communication system. 3. A. the numerical relays are good reliability and chances of failure is very less compared to mechanical relays. This relay has to be installed straight only and away from magnetic field. whenever the rely is activate the  flag also activated. 1 relay can perform only 1 function. benefits, the solid-state relays could be set more precisely (Sachdev et al., 2009). Required fields are marked *. One of the first and simplest advantages is reliability. In this paper the advantages of numerical relay, hardware structure of numerical relay, protection function provided by numerical relay for transformers and control & operation of transformer using numerical relay are discussed in Section I to Section XI. Availability of fault data and disturbance record. With static relays, tripping time of ½ cycle or even less can be obtained. For an electromechanical relay, the amount of voltage and current required to energize the relay coil is. Advantages of Numerical relays. This generation of static relays became quickly very popular and found a large place in power sys-tem protection. Hence there is no mechanical noise. Many functions previously implemented in separate items of hardware can then be included in a single item. In many cases a single microprocessor relay provides functions that would take two or more electromechanical devices. A big difference between conventional electromechanical and static relays is how the relays are wired. Helps analysis of faults by recording details of: Electromechanical relay do not have the ability to detect whether the normal condition has been attained once it is activated thus auto resetting is not possible and it has to be done by the operating personnel, while in numerical relay auto resetting is possible. These relays suffer from the effects of age. When the operating current becomes large, the magnetic field produced by electromagnet is high such that this magnetic field pulls the armature or plunger making the trip circuit contacts to close. Learn about some of the advantages that PLC systems have over a relay system. Input Module 2. Generally we all are knows relay is used to protect the electrical equipment from abnormal condition. Relays are less likely to be turned on by transients than solid-state switches. how to calculate cable size for electrical works, How to calculate KVAR for capacitor bank design, How to calculate short circuit current for transformer. While numerical relay is in compact size and use indication on LCD for relay activation. how the modern numerical relays are used to overcome the disadvantages of electromechanical relays. For example, we have the following protections in numerical relays in-built into one relay. At System Protection we do Retrofitting of Electromechanical Relays with Numerical relays with complete wiring and Testing. 1. The static relay only gives the response to the electrical signal. Electromechanical relays are switches that typically are used to control high power electrical devices. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the... 2. What’s the Difference Between AC and DC Electric Shocks? One of the significant advantages of a solid state relay over an electromechanical relay is its response time (ability to turn on and turn off). The relay hardware consists of standard modules resulting in ease of service. Advantages and Disadvantages of Electro-Mechanical Relays The VA burden of these relays is higher than static and numerical relays. SUMMARY For green field projects numerical relays are preferred over electromechanical relay. Basic hardware is shared between multiple functions, the cost of individual protection functions can be reduced significantly. It has very high life time. the numerical relay having compact size compared to electro mechanical relays, the electro mechanical relays having lot of ... 2. Digital input/Communication module Input Module The Power system operates with analog parameters. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. Compact Size. 1. Following are the benefits or advantages of Solid State Relay: It offers very fast response usually about 1µs ON and 0.5 µs OFF. An EMR may be able to respond hundreds of times per minute, but an SSR is capable of switching thousands of times per minute with no chattering or bounce. What is Alternator? the numerical relay can control multiple functions at a time compared to electro mechanical relay having maximum one control per relay. is first converted into the analogue and digital electrical signal and then act as an input for the relay. Range of operation of electromechanical relays is narrow as compared to numerical relay. The microprocessor based relay furnishes easy interface with digital communication equipment. Reliability. Compact Size. Digital protection can be physically smaller, and almost always requires less panel wiring than equivalent functions implemented using analog technology. 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