US 12,267,040 B2
Method and circuit arrangement for detecting an arc, and photovoltaic (PV) inverter having a corresponding circuit arrangement
Rainer Schmitt, Huenfeld (DE); Marcel Kratochvil, Kassel (DE); and Sybille Pape, Vellmar (DE)
Assigned to SMA Solar Technology AG, Niestetal (DE)
Filed by SMA Solar Technology AG, Niestetal (DE)
Filed on Jul. 15, 2022, as Appl. No. 17/865,573.
Application 17/865,573 is a continuation of application No. PCT/EP2021/050831, filed on Jan. 15, 2021.
Claims priority of application No. 10 2020 100 838.4 (DE), filed on Jan. 15, 2020.
Prior Publication US 2022/0365145 A1, Nov. 17, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H02S 50/00 (2014.01); G01R 31/66 (2020.01); H02J 3/14 (2006.01); H02J 3/38 (2006.01); H02S 40/32 (2014.01); H02S 40/36 (2014.01)
CPC H02S 50/00 (2013.01) [G01R 31/66 (2020.01); H02J 3/14 (2013.01); H02J 3/381 (2013.01); H02S 40/32 (2014.12); H02S 40/36 (2014.12); H02J 2300/24 (2020.01)] 18 Claims
OG exemplary drawing
 
1. A method for detecting an arc in a direct-current (DC) circuit comprising a DC load, a DC source supplying the DC load, and a circuit arrangement arranged between the DC source and the DC load, wherein the circuit arrangement comprises an input comprising two input terminals configured to connect to the DC source, an output comprising two output terminals configured to connect to the DC load, and a switching circuit arranged between the input and the output, wherein the switching circuit or the switching circuit in connection with an output voltage Uout applied to the output of the circuit arrangement is configured to enable a power flow P between the DC source and the output in a first operating mode BM1 and is configured to suppress the power flow between the DC source and the output in a second operating mode BM2, comprising:
cyclically interrupting the power flow P between the input and the output using the switching circuit such that the power flow P is enabled in an active time window with a first period Δt1 in the first operating mode BM1 and the power flow P is suppressed in an inactive time window with a second period Δt2 in the second operating mode BM2,
detecting a current I characterizing the power flow P and/or a voltage U characterizing the power flow P in two consecutive active time windows comprising a current active time window and a preceding active time window,
comparing the detected current I and/or voltage U of the current active time window with the detected current and/or voltage from the preceding active time window, and
signaling an arc if the detected current I and/or voltage U of the current active time window differ from current and/or voltage of the preceding active time window by more than a threshold value,
wherein a duration of the second period Δt2 of the inactive time window is sufficient to quench an arc that may be present in the DC circuit and to suppress reignition of the arc quenched in the inactive time window in the active time window that immediately chronologically follows the inactive time window.