US 12,132,443 B2
Method and circuit arrangement for detecting an arc and photovoltaic (PV) inverter having a corresponding circuit arrangement
Marcel Kratochvil, Kassel (DE); Rainer Schmitt, Huenfeld (DE); Torsten Otto, Ahnatal (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. 17/865,606.
Application 17/865,606 is a continuation of application No. PCT/EP2021/050877, filed on Jan. 15, 2021.
Claims priority of application No. 10 2020 100 838.4 (DE), filed on Jan. 15, 2020.
Prior Publication US 2022/0360214 A1, Nov. 10, 2022
Int. Cl. 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); H02S 50/00 (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)] 20 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 the DC source, an output comprising two output terminals configured to connect the DC load, and a switching circuit arranged between the input and the output and comprises an input capacitance between the input terminals at the input, wherein the switching circuit is configured to enable a power flow P between the DC source and the output in a first operating mode (BM1) and to suppress the power flow P 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 an input current Iin flowing at the input and/or an input voltage Uin applied to the input,
comparing values of the input current Iin and/or input voltage Uin detected in the inactive time window with a current threshold value ITH or a voltage threshold value UTH, respectively, and
signaling an arc presence criterion if the input current Iin detected in the inactive time window falls below the current threshold value ITH and/or the input voltage Uin detected in the inactive time window does not exceed the voltage threshold value UTH.