DC earth fault relay –Working principle

DC earth fault relay is commonly used to detect earth fault in DC systems. An ungrounded DC system is used to control the supply of protection systems, control panels, communication, and other networking devices. When one terminal of the DC system is grounded, it is not creating any problem. However, when both the DC terminal … Read more

Why does Grading Capacitor use in Circuit Breaker?

Grading capacitor is commonly used in High Voltage Circuit Breaker for uniform voltage distribution across the Breaker contacts at CB open position. In a multi-break Circuit Breaker, Grading capacitors are connected in parallel with every break of the CB. Reasons for using Grading Capacitors in Circuit Breakers. When the capacitors are connected across the breaks … Read more

DGA or Dissolved Gas Analysis of Transformer oil

dga in transformer oil

DGA (Dissolved Gas Analysis) is an important tool for checking the healthiness of oil-filled power transformers. Power Transformer is important and expensive equipment in Power Transmission and Distribution systems. Periodic checking or testing of the transformer is done to maintain the healthiness of the transformer. Transformer oil is used for insulation and cooling of the … Read more

Causes of over voltage in Power System

When the voltage goes higher than the rated voltage is called Over Voltage. It is a very common issue in Power systems. System voltage is to be maintained as per the designed voltage for the stability of the power system. All the equipment and insulators used in substations and transmission lines are designed for a … Read more

What is Restriking Voltage? Effects and Methods of Arc Extinction

After opening the Circuit Breaker under load or fault condition, a transit voltage appears across the breaker contacts which is called Restriking Voltage. Frequency of Restriking voltage goes in kH. During arcing period, transient voltage appears across the contacts at or near current zero. If dielectric medium between the CB contacts is greater than the … Read more

What is corona effect? Advantage and Disadvantage of Corona

The Corona Effect is the phenomenon of electric discharge in high voltage transmission lines and substations. Hissing noise and violet glow were observed under the corona effect. Power loss, damage to high voltage electrical components, and noise are observed due to corona discharge in the Transmission line. Why does corona effect in transmission line? Due … Read more

Types of Cable Lugs

Cable lugs are used for termination or connection of cables to the Terminal Box (TB). There are so many types of cable lugs are available based on the cable size. They are mainly copper and aluminum type. Based on the application of the cables, following types of cable lugs are used for cable termination /connection … Read more