What is the difference between digital and numerical relay?

Numerical relays are natural developments of digital relays due to advances in technology. They use one or more digital signal processors (DSP) optimised for real time signal processing, running the mathematical algorithms for the protection functions.

What is the difference between digital and numerical?

As adjectives the difference between numerical and digital is that numerical is of or pertaining to numbers while digital is having to do with digits (fingers or toes); performed with a finger.

What is the difference between numerical relay and static relay?

A big difference between conventional electromechanical and static relays is how the relays are wired. Electromechanical and static relays have fixed wiring and the setting is manual. Numeric relays, on the other hand, are programmable relays where the characteristics and behavior can be programmed.

What is numerical type relay?

Numeric relays are the evolved form of a static and electromagnetic relay. They are basically a device used for measuring electric parameters in an electrical network and convert them into numerical data which undergoes mathematical and logical analysis to decide on tripping an electrical network.

How does a numerical relay work?

Numerical relays use a specialised digital signal processor (DSP) as the computational hardware, along with associated software tools. The relaying voltage and currents are passed through an isolation transformer.

How does a digital relay work?

Relays are switches that open and close circuits electromechanically or electronically. Relays control one electrical circuit by opening and closing contacts in another circuit. As relay diagrams show, when a relay contact is normally open (NO), there is an open contact when the relay is not energized.

What are the advantages of numerical relay?

Advantages of Numerical relays

Compact Size. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays.
Flexibility.
Reliability.
Multi Function Capability.
Different types of relay characteristics.
Digital communication capabilities.
Modular frame.
Low burden.

What are the features of a numerical relay?

What’s the difference between digital and Static relays?

I agree with david about digital, it doesn’t mean a great deal, many people say it but mean to say numerical. but i think digital and numerical relays are not the same, digital relays is similar to static relays but with numerical HMI. do you agree? Sorry, don’t recognize any of those.

How does the DSP work in a numerical relay?

The digital signal processor (DSP) in a numerical relay normally can handle both the relay protection function calculations and general management of the relay such as HMI and I/O. However, if the DSP is overloaded it cannot complete the protection algorithm calculations in the required time and the protection function is slowed.

Which is better numerical relay or numerical protection?

It has some limitations, 1) Unfortunately, the numerical relays have more functionality and greater precision are not necessarily translate into better protection. 2) Numerical Relay can make faster decisions.