An investigation into breaker reclosure strategy for adaptive single pole autoreclosing

The effectiveness of single pole autoreclosure (SPAR) in maintaining power system stability is largely determined by the speed with which secondary arc extinction, and hence autoreclosure, can be achieved. Some work in adaptive autoreclosure has introduced the strong possibility of bringing some measure of adjusting dead times by accurately identifying arc extinction times. However, although the secondary arc extinction time provides a good indication of when to reclose, reclosure of the circuit breakers immediately following arc extinction will normally result in a restrike of the fault. This is because a further finite time is required to allow the fault arc path to deionise fully, so that the transmission line may withstand the full system voltage on reenergisation. The paper is thus concerned with identifying the length of this additional delay period (after secondary arc extinction), so that in conjunction with adaptive autoreclosure techniques, the optimal reclosure time can be determined