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 |
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.
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