SOTF Protection or Switch On To Fault Protection

We are going to discuss here in this article a clear idea about SOTF Protection. Sometimes it becomes necessary to open a circuit breaker just after closing. This is due to the presence of a fault during the closing of the circuit breaker. This type of condition may arise due to different reasons. Such as … Read more

Arc Voltage, Recovery Voltage, Restriking Voltage, RRRV

We will discuss here in details the concept of Arc Voltage, Recovery Voltage, Restriking Voltage, RRRV Basic Concept of Arc Voltage, Recovery Voltage, Restriking Voltage, RRRV When contacts of a circuit breaker open under current carrying condition, electric arcs form in the gap between the contacts. This is due to ionization of the surrounding medium. … Read more

Greenhouse Effect of SF6 Gas and Alternative Gas of SF6

Lifespan and Environmental Impact of SF6 Gas SF6 can stay in the atmosphere up to 3200 years. So, the atmospheric life of SF6 gas is immense. You cannot see it, you cannot feel it, you cannot smell it. The global warming potential is currently 24,000 times more than \(CO_2\). What do I mean by global … Read more

What is a Buchholz Relay? A Complete Working Principle

The Buchholz Relay is a gas-actuated protection relay. It is a mechanical relay. All oil-immersed transformers that have a conservator tank should be equipped with a Buchholz relay. A Buchholz relay can detect both slow-developing faults and major transient faults occurring within the transformer. It provides an early warning (alarm) for slow-developing faults and initiates … Read more

Lightning Arrester – Gapless Metal Oxide (ZnO) Arrester

Why was the gapless ZnO lightning arrester developed over the valve-type lightning arrester? In a valve-type lightning arrester, we connect spark gaps in series with non-linear resistors. This is necessary because silicon carbide (SiC) has a relatively low non-linearity coefficient (α ≈ 5–7). As a result, the knee point in the V–I characteristic of an … Read more

Voltage Regulation in Transmission Line? – A Complete Guide

Power stations generate electric power. Electrical power transmission lines transmit the generated power to far places. The resistance and reactance of the line cause a voltage drop in the power. The Voltage Regulation of Transmission Line is the change in voltage between the sending and receiving ends. What is Voltage Regulation? We express the Voltage … Read more

What is an Oil Surge Relay (OSR)? – A Complete Guide

An Oil Surge Relay, or OSR, is a type of mechanical relay. It operates in response to a sudden oil surge. Need for Separate Diverter Tank Every modern power transformer includes an On-Load Tap Changer (OLTC). During tap-changing operations, some arcing always occurs at the diverter switch contacts. It is desirable to change tap positions … Read more