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As we know numerical relays use DIGITAL SIGNAL PROCESSOR as its computational hardware and based on microprocessor.
WORKING:
Analog input is feed into the anti aliasing filter which is a low pass filter.Output of this filter is feed into the sample and hold circuit , frequency of sampling should be twice of our highest frequency of interest(according to the nyquist criterion).if sampling frequency kept low than aliasing input may occur.
after the sampling, signal are feed into the multiplexer,where all the signal get multiplexed and we have a single signal.this signal is feed into the analog to digital converter.this digital signal is feed into the microprocessor and microprocessor generates control signal according to its input.
for example
if you are using N.R. for over-current protection than you should set a value of current in your program.if the value of current passes through the circuit is greater than the set value..than N.R. enables the circuit breaker and hence our system is protected..
These are microprocessor-based relays in contrast to other relays that are electromechanically controlled. These relays provide great precision and convenience in application in the sophisticated electronic products. By combining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays.
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What are the different types of relays used in substation?
kinds of electrical relays
What are alarm relays?
relays which operate by signalling alarms notifying the type of the fault
What type of protection is used on power transformers?
Depending on the size of the transformer, it can be protected by fuses, thermal elements, or by a full relay protection package, which could include overcurrent relays, differential relays, and distance relays.
Which types of relay is use in power transformer?
A 'power transformer' is a category of transformer used within electricity transmission and primary distribution systems. Relays are widely used with power transformers to provide various types of protection that will act to disconnect the transformer in the event of a fault. Examples of these relays include Buchholz relays, earth-fault relays, and differential relays. Relays are also used to operate a power transformer's automatic tap-changing mechanism in order to compensate for changes in load.
What are current relays?
Current relays are the relay which sens the current passing in particular circuit and operates when this current exceed its set value.
Numerical and microprocessor relay comparison?
Numerical relays are all microprocessor based, but there are relays that take the advantage of microprocessor technology and are not fully numerical. In other words, if a relay is fully based on processing the samples of input signals it is numerical relay.
How can you interfere same lcd display for number of numerical protection relays?
electron
What is Numerical Relays?
These are microprocessor-based relays in contrast to other relays that are electromechanically controlled. These relays provide great precision and convenience in application in the sophisticated electronic products. By combining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays. The first protection devices based on microprocessors were employed in 1985. The widespread acceptance of numerical technology by the customer and the experiences of the user helped in developing the second generation numerical relays in 1990. Modern power system protection devices are built with integrated functions. Multi-functions like protection, control, monitoring and measuring are available today in numeric power system protection devices. Also, the communication capability of these devices facilitates remote control, monitoring and data transfer. Traditionally, electromechanical and static protection relays offered single-function, single characteristics, whereas modern numeric protection offers multi-function and multiple characteristics. Some protections also offer adaptable characteristics, which dynamically change the protection characteristic under different system conditions by monitoring the input parameters. The measuring principles and techniques of conventional relays (electromechanical and static) are fewer than those of the numerical technique, which can differ in many aspects like the type of protection algorithm used, sampling, signal processing, hardware selection, software discipline, etc. First generation numerical relays were mainly designed to meet the static relay protection characteristic, whereas modern numeric protection devices are capable of providing complete protection with added functions like control and monitoring. Numerical protection devices offer several advantages in terms of protection, reliability, and trouble shooting and fault information. Numerical protection devices are available for generation, transmission and distribution systems. The following sections cover relay hardware, relay software, multiple protection characteristics, adaptive protection characteristics, data storage, instrumentation feature, self-check feature, communication capability, additional functions, size and cost-effectiveness.
How many types of relays?
relays are two type 1. Electromagnetic attraction relays. 2. Electromagnetic induction relays.
Numerical value for 500 689?
numerical value for 500689 numerical value for 500689 numerical value for 500689
What is the difference between numerical and non-numerical data?
Numerical data is numbers. Non-numerical data is anything else.
Where are the relays on a citreon xsara?
looking for relays in citreon xzara
When was Kansas Relays created?
Kansas Relays was created in 1923.
Are relays unidirectional or bidirectional devices?
Relays are bidirectional devices.
What is the numerical meaning for microliter?
What is the numerical of micro?
What is numerical sentence?
What is the answers of numerical sentences
What is a numerical expression when you replace it with it's single numerical value?
A numerical expression is ' 2 + 3' A numerical equation is ' 2 + 3 = 5'.
