Switch With Point On Wave Closing

A recloser for a distribution line, the recloser comprising:

• a vacuum interrupter having a fixed contact and a movable contact within a vacuum chamber;
• a magnetic actuator coupled to the movable contact;
• a current transformer connected to harvest operating energy from line current;
• and
• a controller including at least one processor and a memory storing executable code that, when executed, causes the processor to:
• detect fault current;
• open the vacuum interrupter a first time using energy harvested from the current transformer;
• store a polarity of a last half-cycle of the detected fault current associated with completion of the first opening;
• compute a close time such that (i) a first half-cycle of current after reclose has a same polarity as the stored polarity and (ii) a closing drive interval ends at a current zero crossing;
• command the magnetic actuator to close the vacuum interrupter at the close time;
• and
• thereafter execute a reclose-test by opening the vacuum interrupter a second time using energy harvested from the current transformer if fault current persists.