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What is breaker Auto reclose in power system protection

In EHV system, majority of faults occurring in over head lines are of transient in nature. 70 to 80 % of faults are of transient nature i.e. fault is removed after some time.
In case of transient fault, if the line is disconnected from both the ends for a very short period, say about 1 sec, to allow fault arc to deionized and regain its dielectric strength, the line can be recharged at both the ends immediately afterwards.
The security of the supply system is thus enhanced considerably and the stability of system is also maintained.
Presently, auto reclose feature is applied with all 400 KV lines of Electricity company and 400KV inter state lines.
Selection for auto reclose can be 1 phase or 3 phase.
If auto reclosing produces very much less torsional fatigue than 3 phase auto reclose.
The main advantage of If auto reclose is that during the De-ionization time, when one phase is opened, power transfer takes place through the other healthy phases & neutral and thus synchronization is maintained
In order to reduce arc De-ionization time in 400KV system, reluctance of sufficient capacity is provided at both ends of line in all 3 phase and neutral, particularly for line length more than 200 Km.

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