Protection

What is Tower Footing Resistance? - Its Reduction Methods

The resistance offered to the lightning current when the tower is directly exposed to lightning is called tower footing resistance. It is the value of footing resistance measured at 50 Hz. The performance of the line purely depen…

Solid Grounding or Effective Grounding - Working & Advantages

When the neutral of the system is directly connected to the ground with negligible resistance and reactance between them, then the grounding system is known as solid grounding or effective grounding. A system is said to be solidl…

Resistance Grounding - Working, Phasor Diagram & Advantages

The system in which the neutral point is grounded through a current limiting device (resistor) is known as a resistance grounded system and the grounding is referred to as resistance grounding. This method is used when it becomes…

Reactance Grounding - Operation, Advantages & Disadvantages

The system in which the neutral point is grounded through impedance which is highly reactive is known as reactance grounded system and the grounding is referred to as reactance grounding. Necessity of Reactance Grounding : If s…

What is Neutral Grounding? - Definition, Types & Advantages

The neutral grounding is nothing but connecting the neutral point of the supply system or rotating machine or transformer to the earth directly or through some circuit elements. A three-phase system can be operated in two ways, t…

What is Arcing Ground? - Protection Against Arcing Ground

Phenomenon of Arcing Ground : Due to lightning surges, puncture of an insulator on an overhead line, falling of a branch, etc., an arc between the phase conductor and earth develops. The arc extinguishes and restrikes in a repea…

What is Peterson Coil? - Its Function in Neutral Grounding

The Peterson coil is an adjustable iron-cored reactor connected between the neutral point and ground. It has the capability of producing resonance by turning the capacitance of the healthy phases during a line to ground fault. It…

Ungrounded Neutral System - its Behaviour & Disadvantages

The ungrounded neutral system is a neutral system in which there is isolation between neutral and ground i.e., there is no electrical connection between neutral and ground. Hence the ungrounded neutral system is also called an is…

Overvoltage or Voltage Surge in Power System - its Causes

The overvoltage or transients or surge voltages are the voltages whose values are much more than the normal voltages. These are of short duration which can cause malfunction or failure of equipment in the system depending upon th…

Necessity of Ground Wire in Overhead Transmission Lines

A transmission system should be equipped with an effective protection system to prevent direct strikes of lightning strokes on the phase conductors. The protection system should also create a path over insulated structures for c…

Transmission Line Distance Relay Protection

The distance protection scheme is widely employed for the protection of very long high voltage transmissions lines and sub-transmission lines which provide discrimination protection without employing pilot wires. Distance relay o…

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