A transmission switching system is an essential component of the electricity supply network. It enables electricity transmission from one line to another for end users. It also helps ensure that …
Earthing does not guarantee that humans will be safe when they come into contact with live conductors. Although relays may be installed to detect earth leakages, typically their settings are …
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 …
The Motor Control Centre is used in general to describe combinations of enclosures, busbars, circuit breakers, power contactors, power fuses, protective relays, controls and indicating devices. Read more about switchgear …
The use of overcurrent relays is the simplest and cheapest type of line protection. Three types of overcurrent relays are used: Inverse time delay overcurrent (TDOC) relays, Instantaneous overcurrent relays, …
Gas-insulated substations (GIS) have been used in power systems over the last three decades because of their high reliability, easy maintenance, small ground space requirement, etc. This article is an …
As per IEC 60947, switchgears with rated voltages up to 1000 V ac and 1500 V dc are termed as low voltage switchgear. The term ‘switchgear’ is a generic term …
In this post, we will explain Instantaneous, Inverse Time and Definite Time Lag Relays and their characteristics. An important characteristic of a relay is its time of operation. By ‘the time …
We have already given an introduction to substation earthing system in an article published earlier. Today we are going to discuss the design of substation earthing system. Before 1960s the …
Most of the relays used in the power system operate by virtue of the current and/or voltage supplied by current and voltage transformers connected in various combinations to the system …
What is a Static Relay? There are two basic classifications of relays – Electromechanical Relays and Solid State Relays (Static relay). One main difference between them is electromechanical relays have …
In this post, we will look into protective zones in the power system and why they are overlapped. What is a Protective Zone in Power System? A protective zone is …
Protective relaying is necessary with almost every electrical plant, and no part of the power system is left unprotected. The choice of protection depends upon several aspects such as type …
Primary and Back-up Protection Primary protection (Main protection) is the essential protection provided for protecting an equivalent/machine or a part of the power system. As a precautionary measure, addition protection …
We have already discussed the working of electrical relays. Now we are going through different types of electrical relays. There are two basic classifications of relays: Electromechanical Relays Solid State …
We usually think of an electric power system in terms of its more impressive parts – the big generating stations, transformers, high-voltage lines, etc. While these are some of the basic elements, …
