US 11,996,488 B2
Disconnection of a string carrying direct current power
Liron Har-Shai, Tel Mond (IL); Alon Zohar, Netanya (IL); Yoav Galin, Raanana (IL); and Meir Adest, Modiin (IL)
Assigned to Solaredge Technologies Ltd., Herzeliya (IL)
Filed by Solaredge Technologies Ltd., Herzeliya (IL)
Filed on Jan. 28, 2022, as Appl. No. 17/587,358.
Application 17/587,358 is a continuation of application No. 15/934,358, filed on Mar. 23, 2018, granted, now 11,271,394.
Application 15/934,358 is a continuation of application No. 15/076,887, filed on Mar. 22, 2016, granted, now 9,935,458, issued on Apr. 3, 2018.
Application 15/076,887 is a continuation of application No. 13/315,754, filed on Dec. 9, 2011, granted, now 9,401,599, issued on Jul. 26, 2016.
Claims priority of application No. 1020862 (GB), filed on Dec. 9, 2010.
Prior Publication US 2022/0200273 A1, Jun. 23, 2022
Int. Cl. H01L 31/02 (2006.01); H02H 7/20 (2006.01); H02J 3/46 (2006.01); H02H 3/16 (2006.01); H02H 3/33 (2006.01); H02J 3/38 (2006.01)
CPC H01L 31/02021 (2013.01) [H02H 7/20 (2013.01); H02J 3/46 (2013.01); H02H 3/16 (2013.01); H02H 3/33 (2013.01); H02J 3/381 (2013.01); H02J 2300/24 (2020.01); Y02E 10/56 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
connecting an isolator in series with a positive power line of a photovoltaic (PV) string, wherein the isolator comprises at least one relay and at least one switch connected in parallel;
measuring, at multiple times, a difference between a current in one direction in the positive power line of the PV string and a return current in an opposite direction in a negative power line of the PV string;
detecting, based on the measuring, a change in the difference from being below a predetermined value to above the predetermined value; and
in response to the detecting:
controlling the at least one relay, and the at least one switch, to open;
measuring, in response to the controlling, a voltage across the isolator;
determining, based on the measured voltage, that the at least one switch or the at least one relay is conducting; and
based on the determining, raising an alarm.