## What is busbar differential protection?

Current Differential Protection. The scheme of busbar protection, involves, Kirchoff’s current law, which states that, total current entering an electrical node is exactly equal to total current leaving the node. Hence, total current entering into a bus section is equal to total current leaving the bus section.

### What are the two types of protection given for busbar?

This type of busbar protection has two types: low-impedance biased differential protection and high-impedance differential protection, as described here.

#### Which protection system is used for busbar?

The differential protection scheme is used both for the protection of the phase-to-phase fault and for the ground fault. Schematic diagram of bus differential protection relay is shown in the figure below. The current transformers are placed on both the incoming and the outgoing end of the bus-bar.

What is line differential protection?

Line differential protection is one of the most popular forms of transmission line protection. This type of protection is based on Kirchoff’s current law, which states that the current flowing into a line must be equal to the current flowing out of the line.

What is LBB protection?

LBB stands for Local Breaker backup, and it is used as a backup protection of the circuit breaker to isolate the fault in case the circuit breaker is failed to trip. It is also called Breaker failure relay (BFR) or 50BF. ANSI code of LBB protection is 50Z.

## What is reverse blocking protection?

Reverse Busbar Blocking Scheme. The reverse busbar protection is a cost-effective solution for accelerated clearance of busbar faults in distribution systems. It can only be applied on single busbars with a fixed direction of power-flow and fault current flow. In picture 3, a typical application is shown.

### Where is differential relay used?

Generally, differential relays are used to protect the equipment against internal faults. Merz price protection scheme is one form of the differential relay which is used to protect the stator winding of Alternator from the internal faults. Differential relay is also used for the protection of transformer winding.

#### What is diff protection?

Differential protection is a unit-type protection for a specified zone or piece of equipment. It is based on the fact that it is only in the case of faults internal to the zone that the differential current (difference between input and output currents) will be high.