The differential relay acts as main protection whereas the over current and earth fault relays act as backup protection for the alternator. Overunder voltage relays are extensively used in power system protection. Microprocessor based inversetime multiple overcurrent relays the use of microprocessors to implement single and multiple overcurrent relays has been reported in the literature. This project is about designing the controls of an overcurrent relay using microcontroller. A relay is an electromagnetic switch that is used to turn on and turn off a circuit by a low power signal, or where several circuits. Jay and rohit, kumar 2014 development of microcontroller based overcurrent relay controls. Microcontroller based instrument identification and detection. The use of microcontrollerbased relays has become very common.
Power transformer protection using microcontrollerbased relay article pdf available in journal of applied sciences 712 december 2007 with 12,152 reads how we measure reads. This system provides a better and safer protection than the other methods. Dvm electrical electricity electronics energy ic ic741 igbt transistor inductor inductors integrated circuits led light lvdt meter microcontroller microprocessor mosfet motor photodiode plc pn junction power power supply rectifier resistors scr. It has a limitation that it can be applied only to simple and non costly equipments. Overcurrent protection of transformer by incorporating idmt. For most hobby projects, the output that the relay will drive would probably not be much, may be a few hundred milliamperes or in some cases, a couple of amperes. Design and implementation of microcontrollerbased multifunction relay tdoc results future work purpose advantages of controllerbased multifunction relay. Introduction overload relay is a type of protective relay which. Microcontroller based overcurrent relay and directional. The space requirement for the microprocessor based relay. The space requirement for the microprocessorbased relay. In this article, the basics of a relay like energized relay and deenergized relay are explained in detail. To design and fabricate over current protection relay using pic micro controller which can operate on the permissible conditions by setting the over current value.
Di is the input for address and data from the microprocessor to atmel ata6842. Liew department of electrical engineering, ivational unmersrty of singapore, 10 kent ridge cresccn, singapore 119260. In this project an overvoltage and overcurrent relay which is made using a microcontroller. The nc terminal is normally connected to the commonpole and the no is normally kept open. Microprocessor based overcurrent relay polytechnic hub. On closer examination it turns out that the microprocessor based relay is a small computer in which the output circuits usually builtin ct or vt fig. See the block diagram of driver circuit which i used in my project. I understand what plagiarism is and i am aware of the universitys policy in this regard 2.
Under impedance relay distance relay auto synchronising synchrocheck relay ac under voltage relay power directional relay under current mor under power relay field control loss of field relay dc over voltage relay reverse phase or phase balance current relay phasesequence or singlephasing voltage relay machine or transformer thermal irelay. Microcontroller based overcurrent relay and directional overcurrent relay with ground fault. To test unwanted conditions over current and when such conditions arise to isolate the fault condition in the shortest possible time. The relay can be on or off, that is, it has two stable states. The system includes facilities for discrimination between internal fault current and magnetizing inrush current, differential protection, over current protection, over. In this project, pic microcontroller will be used to control and operate. Overcurrent protection of transformer by incorporating. Microcontrollerbased overcurrent protective relay all. Pdf protection of power transformer using microcontrollerbased. Overcurrent condition implies overheating of transmission cables with respect to time. Ata6842 microcontroller based overcurrent relay k 718 ek15s ata6842p std1802 b2cg atmel 717 ek15 text. To interface relay with microcontroller we need a driver circuit to drive the power to relay. Title of the work design of a microcontroller based power transformer protection declaration 1. Power transformer protection using microcontrollerbased relay.
Im using pic16f877a chip along with ql200 development board. It owes its application from the fact that in the event of fault the current would increase to a value several times greater than maximum load current. Before we begin, i want to introduce the relay to you. Microcontroller based relays are more popular because of no mechanical operation. The overcurrent relay is defined as the relay, which operates only when the value of the current is greater than the relay setting time. All of these functions can be achieved using transistors as well. The question arises if the microprocessorbased protection device is a relay in the full sense of the word. How to drive a relay using microcontrollers vishnus blogs. The transistor is driven into saturation turned on when a logic 1 is written on the port pin thus turning on the relay. Also, the design, construction, working, applications, and also relay selection is explained in detail. Microprocessorbased overcurrent relays article pdf available in ieee transactions on industrial electronics ie331. The protective relays that may be tested by our developed relay testing system are.
Microprocessor based over current relay current is taken from c. Protection of power transformer is a big challenge nowadays. Idmt relays usually uses eddy current effect for attaining inverse definite minimum time idmt relation but by using a microcontroller instead, will give relay more appropriate operation and better time response. A novel approach to overvoltage and overcurrent protection of simple single 101 operated ac 250v 10a relay. The microprocessor based scheme also includes a singlezone microprocessor based relay as a backup in case of failure of the primary multizone relay. Design a circuit with led display, rtc, pot, switch, relay and micro controller. This paper presents the design and construction of overcurrent and directional overcurrent relays with ground fault protection for the protection of threephase. Many utilities are taking advantage of the new features and innovations offered in these relays. Microprocessor based overcurrent relays article pdf available in ieee transactions on industrial electronics ie331. Microcontroller based instrument identification and detection free download as powerpoint presentation. If the utility applies a lowside transformer overcurrent relay, there is no additional cost except for the control wiring of the trip circuit. Microcontroller based overcurrent relay and directional overcurrent relay with ground fault protection. The ieee device number used to signify a directional element is either a 21 impedance element, based on zvi, and having a distance to fault capability or a 67 directional overcurrent, generally based on the phase. This arduinobased prs featured in this study will be using an atmel microcontroller.
Index termsarduino uno board, atmega328, faults, micro controller, over current relay, proteus 8 professional. Figure 4 shows the circuit diagram of the over current protection of 1 kva transformer with pic microcontroller using numerical relay. The microcontroller is programmed in such a way that it will perform its action whenever there is abnormal conditions such as overvoltage or overcurrent. The undervoltage supervision unit has an influence on the tripping delay of the overcurrent and shortcircuit steps by switching two setting points. Microprocessorbased distribution relay applications.
In this project, pic microcontroller will be used tocontrol and operate the tripping coil in circuit breaker. A novel approach to overvoltage and overcurrent protection. The voltage controlled time overcurrent relay mri1iu is the combination of a time overcurrent relay basic unit mri1 and an additional undervoltage supervision unit. Development of microcontroller based overcurrent relay controls. I declare that this final year project is my original work and has not been submitted elsewhere. In this paper it is shown that several independent overcurrent relays and other tasks can be implemented using a single microcontroller. Microcontroller based instrument identification and. The question arises if the microprocessor based protection device is a relay in the full sense of the word. Depending on the time of operation the overcurrent relay is categorized into following types. Microcontroller based relays offer many advantages and benefits over electromechanical relays they are. Other types of relays also used know as solid state relay in which dc voltage used as input. Nov 24, 20 a set of instructions written for the microcontroller to perform a task is called a program and a group of programs is called software. Type micro51 and micro51ft microprocessorbased timeovercurrent relays english pdf catalogue type micro51 and micro51ft microprocessorbased timeovercurrent relays english pdf manual related offering.
Design of microcontroller based multifunctional relay. In the case of the directional overcurrent relay, the direction of the current flow is identified to determine whether the fault current is flowing into. The relay module can tolerate an electric current upto 10 a and it can be programmed to trip the circuit at any value of current below the maximum. Working of relayshow relay works,basics,design,construction. Hi there, im new to this forum and to the world of pic microcontrollers programming. Sampling rates, analogtodigital converter resolution, record format, and other parameters have not been standardized 6. Here i used diode d11n4148ws, resistor r1 1k, transistor t1 bc547, 12 v power supply and 6v relay. How much current is required to energize the relay and what is the voltage rating. Initially, pic microcontroller is programmed using mplab development tool based on the values obtained from fault analysis shown in table 7.
Jan 22, 20 protection of power transformer is a big challenge nowadays. Implemented design is basically a system on microcontroller 4. As you can see an npn transistor bc547 is being used to control the relay. Keywords circuit breaker, distribution transformer, overload, microcontroller, relay. Microprocessor based over current relay polytechnic hub. Microcontroller do not have considerable amount of current to operate relay. By the help of microcontroller based relay, protection of transformer is performed very quickly and accurately. Previous figure represents a block diagram of proposed microcontrollerbased over current relay. Keywords adc, differential relay, embedded c programming, i to v converter, pic microcontroller. Overcurrent relays, undercurrent relays, frequency relays, ground fault relays, directional ground fault relays. Electric power systems research 38 1996 11 i7 microcontroller based overcurrent relay and directional overcurrent relay with ground fault protection zhijun gan, s. The microprocessorbased scheme also includes a singlezone microprocessorbased relay as a backup in case of failure of the primary multizone relay. I have a project im working on which is to design a microcontroller based overcurrent protective relay.
This post will outline how you can drive a relay using micro controllers like avr. Relay logic is very important to understand the microprocessorbased relay. Read microcontroller based overcurrent relay and directional overcurrent relay with ground fault protection, electric power systems research on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Breaker failure protection many microprocessorbased distribution relays are equipped with internal timers that, along with a relay. At first the protection of singlephase system is considered for the explanation of microcontroller based system working as a relay. Microcontroller based protective relay testing system. This system provides a better and safer protection than the other methods which are currently in use. Starting current of motors exceed the rated current at a certain. Microprocessor based inversetime multiple overcurrent relays. Microprocessor based inversetime multiple overcurrent. Microprocessorbased protective relays applications in. On closer examination it turns out that the microprocessorbased relay is a small computer in which the output circuits usually builtin ct or vt fig.
Pdf design of microcontroller based generator protection scheme. It protects the equipment of the power system from the fault current. Over current oc relay is a type of relay which performs its switching action based on an input current to it. Aug 17, 2017 figure 1 shows the basic relay driver circuit. Over current relay working principle types electrical4u. To design and develop an over current protection relay using microcontroller which can operate on the permissible conditions by setting the over current value.
The secondary of the transformer is connected to the ammeter 010 amps to. Microprocessor based time overcurrent relay micro51 micro51 microprocessor based overcurrent relays are used for phase and ground overcurrent protection in utility, industrial and commercial electrical power systems. To design and fabricate over current protection relay using pic micro. The setup consists of current transformer, potential transformer, and relay and contactor unit along with pic microcontroller. The input to the tranformer is gs iven from the supply of 230 volt, 50 hz supply. What will be connected to the relay output and how much current is required for the relay output. This is the simplest of the ways to protect a line and therefore widely used. A novel approach to overvoltage and overcurrent protection of. International journal of technical research ijtr vol. Similarly, the output of a logic function is activated, that is, high or deactivated, that is, low. Directional overcurrent relays ground fault protection overcurrent relays relay protection. Microcontroller based overcurrent relay and directional overcurrent. Although there are different types of overcurrent relays but basic working principle of overcurrent relay is more or less same for all.
I declare that this final year project is my original work and has not been submitted elsewhere for examination, award of a degree or publication. Breaker failure protection many microprocessor based distribution relays are equipped with internal timers that, along with a relay. The relay obtains the system currents at the rate of 12 samples per cycle and estimates the fundamentalfrequency components of the current signals using discrete fourier transform techniques. Improved monitoring and control functions the use of microcontroller based relays has become very common. Concepts are same for any other micro controller used either in standalone mode or embedded in a development board like netduino or arduino. Dvm electrical electricity electronics energy ic ic741 igbt transistor inductor inductors integrated circuits led light lvdt meter microcontroller microprocessor mosfet motor photodiode plc pn junction power power supply rectifier resistors scr semiconductor textile. In this project, pic microcontroller will be used to control and operate the tripping coil in circuit breaker. Microcontroller based lowset oc is highset oc ihs lowset ef. Jun 01, 2010 hi there, im new to this forum and to the world of pic microcontrollers programming.
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