Maintaining the digital relay data in digital format has the. Another important advantage of the microprocessor based relay is that a microprocessor unit can perform the retransmission operation of several systems. Microprocessor based over current relay current is taken from c. Attempts, alarm contacts, security logs, setting file access, locking settings files, device firmware, traceability of. Relay scheme design using microprocessor relays a report to the. A datadriven approach derrick haas, matt leoni, karl zimmerman, adrian genz, and travis mooney, schweitzer engineering laboratories, inc. Microprocessorbased protective relays deliver more. In general terms, auxiliary and tripping relays are supplied in 50mm cases. The space requirement for the microprocessor based relay scheme is much less than the electromechanical relay scheme 5, 6. Relay selection guide ge grid solutions online store. Activating the contact unit using electromagnetic attraction, which is produced when electric current exceeding the. The statistical data introduced by the author coincide with data of other authors and con. Hence domestic and industrial facilities are increasingly investing in microprocessor based relays to. The idmt relay on the hv side is also provided with an instantaneous overcurrent element.
Microprocessorbased relays, also called digital relays, have a proven track record of. Typical examples are rez 1 universal phase and ground distance relay for. In that era, the efforts were concentrated to obtain a very high speed fault clearance. Abstractthe common format for transient data exchange comtrade file format is an ieee standard by which power. The goal of this paper is to contribute to the better understanding of microprocessor based 87l relays. Configuration mechanisms of modern microprocessorbased relays. Your microprocessor based controller has been designed to monitor and control the conductivity of your process water. Abstract microprocessor based protective relays have. The program can handle the online calculations and make the decision accordingly. During this process, some formatting and fonts were changed.
Understanding the limitations of replaying relaycreated. The controller energizes two relay outputs based on a bleed and feed mode of operation. Life cycle experiences with microprocessor based relays and roadmap to sustainability. By using the boolean simplification, we can represent the logic in a microprocessor based relay in a few different ways. Microprocessor based relays provide technical improvements and cost savings in several ways. Microprocessor is that these are general purpose electronic processing devices which can be programmed to execute a number of tasks microprocessor is its speed, which is measured in hertz. Substation commissioning to verify correct data reporting between a host device and an ied is a tedious and lengthy process.
For instance, a microprocessor with 3 ghz, shortly ghz is capable of performing 3 billion tasks per second. Microprocessor relays with logic and communication capabilities can accomplish this type of scheme by using either hardwired trip contacts or by using communication signals between each other to transfer statuses. Commissioning microprocessor based ied communication. A big difference between conventional electromechanical and static relays is how the relays are wired. Micro51 microprocessor based overcurrent relays are used for phase and ground overcurrent protection in utility, industrial and commercial electrical power systems. The article is a continuation of a set of the authors previous publications about the reliability of the microprocessor based protective devices. The relay testing handbook 8d download ebook pdf, epub. There are some advantages of microprocessor are given below. The se701 is a microprocessor based groundfault relay for resistance and solidlygrounded systems. Aging microprocessor devices approaching 20 years service.
Click download or read online button to get the relay testing handbook 8d book now. Microprocessor based overcurrent relays article pdf available in ieee transactions on industrial electronics ie331. Conventional relays like electromechanical relays employed bulky sized mechanical comparators which reduced their speed and these relays often served a single function and a single characteristic. Integrity of data exchange between the field devices and a host. The microprocessor based relay furnishes easy interface with digital communication equipment. Microprocessorbased distribution relays provide technical improvements and cost savings in. In utility and industrial electric power transmission and distribution systems, a digital protective relay is a computer based system with software based protection algorithms for the detection of electrical faults.
The references provide the required background knowledge and allow for further reading to explore some of the topics in greater detail. In some solid state relays, a simple microprocessor does some of the relay logic, but the logic is fixed and simple. Microcontroller based overcurrent relay and directional. Unit i introduction of relays a relay comprises of an electromagnet and a contact unit. Numerical relays are based on the use of microprocessors. The series 985 pdf was created by scanning pages and then recapturing the text to minimize the size of the file. Microprocessor based relays, also called digital relays, have a proven track record of reliability, with over 100,000 relay years of field experience. Microprocessorbased distribution relay applications. Microprocessorbased motor relay including the following functions.
Understanding microprocessor based relay logic part 1. The se701 can provide mainplant protection, feederlevel protection. Problems and solutions 337 examining the relay s reaction in supplying the signal to them. Schwartz, schweitzer engineering laboratories, inc. In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker when a fault is detected 4 the first protective relays were electromagnetic devices, relying on coils operating on moving parts to provide detection of abnormal operating conditions such as overcurrent, overvoltage, reverse power flow, overfrequency, and underfrequency. In this paper the implementation of an impedance relay using 8085 microprocessor is described. Tests of microprocessorbased relay protection devices. The functions of electromechanical protection systems are now being replaced by microprocessorbased digital protective relays, sometimes. The fireye burnerpro is a comp act, microprocessor based, primary flame safeguard control system designed to provide the proper burner sequencing, ignition and continuous flame monitoring for onoff, multistage, or modulating burners used in commercial. Understanding microprocessor based relay logic part 4 relay settings and test procedures duration. In practice it has turned out that most mpds simply do not sense the substitution of the whole printed board of one kind for the board of other kind which is not compatible with relay current settings.
These microprocessor based range of relays are mounted in 50, 100, 150 and 200mm wide drawout cases. If you have trouble reading any pages, please contact watlow and these can be sent or faxed to you. That kit used for this purpose is vinytics vmc 8506 which has an inbuilt adc interface based on adc0809 chip and also some relays which can be turned on or off by providing simple 8085 instructions. In previous publications the author has already analyzed the transition from electromechanical to a microprocessor based protective relays, and considered the prospects and problems of microproc. Modern microprocessor relays are much more powerful than their predecessors and testing. If the capacitor switches are open and the capacitor control is in manual, close the. They are functional replacements for electromechanical protective relays and may include many protection.
The majority of mref, feeder, transformer, generator and motor protection relays. This site is like a library, use search box in the widget to get ebook that you want. Entering setpoints to the microprocessor based relay is made easier by use of a keypad and a lcd display to guide the user. In addition to customizing specific microprocessor based relay capabilities, skilled integration engineers can also help utilities and industrial facilities design their microprocessor based relay protection systems in such a way as to fully leverage the inherent benefits of the relays and maximize each relay s value. At first it was hybrid solutions, where the time critical filtering was performed with analogue electronics.
Microprocessor based relays are prefer able because several types of characteristics can be an overcurrent relay algorithm normally includes a implemented in the same hardware or with a minimum digital filter to extract the fundamentalfrequency com change of hardware 1,2. The manuals are available as searchable pdf files with bookmarks and other features. Compared to static relays, digital relays introduce analogue to digital convertor ad conversion of all measured analogue quantities and use a microprocessor to implement the protection algorithm. Life cycle experiences with microprocessor based relays. The relays use programmable logic to reduce and simplify wiring. The microprocessor may use some kind of counting technique, or use the discrete fourier transform dft to implement the algorithm. Description the powerlogic digital relay figure 1 is a multifunction, microprocessor based device which performs these functions. These include common hardware platforms, configuring the software to. In addition to customizing specific microprocessorbased relay capabilities, skilled integration engineers.
Typical electromechanical relay scheme panel layout. Microprocessor based relays are computers with preset programming using inputs. The micro51 operates from conventional 5a or 1a secondary current transformers. Microprocessorbased protective relays applications in. Microprocessorbased distribution relay applications schweitzer. The relay is operated in three zones with the required delay based on impedance. Tutorial on operating characteristics of microprocessor. When the conductivity measurement goes above the user defined set point, 2 two relays are. Numerical relays protection and control products for. Thus various advantages of microprocessor based relay are. A microprocessorbased relay applies programmable logic to establish. Integral to microprocessor based relay tc2 cc in1 breaker status input in2 trip circuit monitor input optional. Different techniques and algorithms were proposed for achieving this objective.
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