What are the applications of autorecloser?

Answer 1

An autorecloser is a feature built into a high-voltage circuit breaker. In the event of a transient fault (e.g. a tree branch hitting a conductor) to an overhead line, the circuit breaker will trip and disconnect the line. However, the autoreclosing feature will then automatically reclose the circuit breaker. If the fault has cleared itself, then the line will remain energised. If the fault persists, then the autorecloser attempt to reclose the circuit breaker a set number of times before locking the circuit breaker open.

The number of times the autorecloser feature will attempt to reclose the circuit breaker, and the duration between attempts, can be set by the protection engineers.

This autoreclosing feature of circuit breakers is often used in conjunction with sectionalisers. These are pole-mounted switches which are located at different points along a power line. When the circuit breaker trips, in response to a line fault, the furthest sectionaliser along the line disconnects the furthest section of line. If the fault remains when the circuit breaker then recloses, the next nearer sectionaliser disconnects the line from its location. This action continues, until the permanently-faulty section of line has been disconnected. This system tries to ensure that as much of the healthy part of the power line remains in use as possible, following a permanent fault.