Junction box having parallel switch failure detection
A junction box comprises parallel-connected switches comprising at least a first switch and a second switch. A first current sensor senses current through the first switch. A second current sensor senses current through the second switch. A controller is in communication with the first and second current sensors. The controller modifies operation of the junction box in response to detecting at least one of the switches is failed. The controller detects that one of the first switch and the second switch is failed when the current through the first switch and the current through the second switch are unbalanced.
1 . A junction box, comprising:
a plurality of parallel-connected switches comprising at least a first switch and a second switch;
a first current sensor sensing current through the first switch;
a second current sensor sensing current through the second switch; and
a controller in communication with the first and second current sensors, the controller adapted to modify the operation of the junction box in response to detecting at least one of the first switch and the second switch failed and wherein the controller is adapted to compare the current through the first switch with the current through the second switch and detect that one of the first switch and the second switch failed based on an imbalance between the current through the first switch and the current through the second switch.
2 . The junction box of claim 1 , wherein:
the controller detects that the first switch failed when the current through the first switch is less than the current through the second switch.
3 . The junction box of claim 1 , wherein:
the controller detects that the first switch and the second switch are in a proper order when the current through the first switch and the current through the second switch are balanced.
4 . The junction box of claim 1 , wherein:
the plurality of parallel-connected switches further comprise;
a third switch and a fourth switch;
the first current sensor sensing current through the first switch and the third switch;
the second current sensor sensing current through the second switch and the fourth switch; and
the controller detects that one of the first switch and the third switch or one of the second switch and the fourth switch failed when the current through the first switch and the third switch and the current through the second switch and the fourth switch are unbalanced.
5 . The junction box of claim 4 , wherein:
the controller detects that one of the first switch and the third switch failed when the current through the first switch and the third switch is less than the current through the second switch and the fourth switch.
6 . The junction box of claim 5 , wherein:
the controller detects that the first switch failed when the current through the first switch and the third switch, while the first switch is controlled by the controller to be open, is greater than the current through the first switch and the third switch while the third switch is controlled by the controller to be open.
7 . The junction box of claim 4 , wherein:
the controller detects that the first switch, the second switch, the third switch, and the fourth switch are in a proper order when the current through the first switch and the third switch and the current through the second switch and the fourth switch are balanced.
8 . The junction box of claim 1 , wherein:
the plurality of parallel-connected switches comprise a first set of switches comprising the first switch and a second set of switches comprising the second switch, the first set of switches and the second set of switches comprising a same number of switches;
the first current sensor sensing current through the first set of switches;
the second current sensor sensing current through the second set of switches; and
the controller detects that one of the switches of the first set of switches or one of the switches of the second set of switches failed when the current through the first set of switches and the current through the second set of switches are unbalanced.
9 . The junction box of claim 8 , wherein:
the controller detects that one of the switches of the first set of switches failed when the current through the first set of switches is less than the current through the second set of switches.
10 . The junction box of claim 1 , wherein:
the plurality of parallel-connected switches comprise a first set of switches comprising the first switch, a second set of switches comprising the second switch, and at least one or more set of switches, the first set of switches, the second set of switches, and each of the at least one or more set of switches comprising a same number of switches;
the first current sensor sensing current through the first set of switches;
the second current sensor sensing current through the second set of switches;
at least one or more current sensors sensing current through the at least one or more set of switches, respectively; and
the controller detects that one of the switches of the first set of switches, one of the switches of the second set of switches, or one of the switches of the at least one or more set of switches failed when the current through the first set of switches, the current through the second set of switches, and the current through the at least one or more set of switches are unbalanced.
11 . The junction box of claim 1 , wherein:
the controller modifies operation of the junction box in response to detecting at least one of the switches failed by modifying operation of one or more of the switches.
12 . The junction box of claim 1 , wherein:
the controller generates a warning notification in response to detecting at least one of the switches failed.
13 . The junction box of claim 1 , wherein:
the plurality of parallel-connected switches are connected in parallel between a battery and a load.
14 . The junction box of claim 1 , wherein:
each of the current sensors comprises an amplifier and a shunt resistor.
15 . A non-transitory computer readable storage medium comprising stored computer executable instructions to cause a controller to:
sense, with a first current sensor, current through a first switch of a plurality of parallel-connected switches comprising at least the first switch and a second switch;
sense, with a second current sensor, current through the second switch; and
modify operation of one or more of the switches in response to detecting at least one of the switches failed, wherein the controller is adapted to compare the current through the first switch and the current through the second switch and detect that one of the first switch and the second switch failed based on an imbalance between the current through the first switch and the current through the second switch.
16 . The non-transitory computer readable storage medium of claim 15 , further comprising stored computer executable instructions to cause the controller to detect that the first switch failed when the current through the first switch is less than the current through the second switch.
17 . A method, comprising:
sensing, by a first current sensor, current through a first switch of a plurality of parallel-connected switches comprising at least the first switch and a second switch;
sensing, by a second current sensor, current through the second switch; and
modifying, by a controller in communication with the first and second current sensors, operation of one or more of the switches in response to detecting at least one of the switches failed, wherein the controller is adapted to compare the current through the first switch and the current through the second switch and detect that one of the first switch and the second switch failed based on an imbalance between the current through the first switch and the current through the second switch.
18 . The method of claim 17 , further comprising:
detecting, by the controller, that the first switch failed as the current through the first switch is less than the current through the second switch.
19 . The method of claim 17 , further comprising:
sensing, by the first current sensor, current through a first set of switches comprising the first switch, the first set of switches being of the plurality of parallel-connected switches;
sensing, by the second current sensor, current through a second set of switches comprising the second switch, the second set of switches being of the plurality of parallel-connected switches, the first set of switches and the second set of switches comprising a same number of switches; and
detecting, by the controller, that one of the switches of the first set of switches or one of the switches of the second set of switches failed as the current through the first set of switches and the current through the second set of switches are unbalanced.
20 . The method of claim 17 , further comprising:
sensing, by the first current sensor, current through the first switch and a third switch of the plurality of parallel-connected switches further comprising the third switch and a fourth switch;
sensing, by the second current sensor, current through the second switch and the fourth switch; and
detecting, by the controller, that one of the first switch and the third switch or one of the second switch and the fourth switch failed as the current through the first switch and the third switch and the current through the second switch and the fourth switch are unbalanced.