US 12,132,445 B2
Device and method for detecting a fault current in a photovoltaic installation, and photovoltaic inverter comprising the device
Martin Sabban, Kassel (DE)
Assigned to SMA Solar Technology AG, Niestetal (DE)
Filed by SMA Solar Technology AG, Niestetal (DE)
Filed on Dec. 1, 2022, as Appl. No. 18/072,749.
Application 18/072,749 is a continuation of application No. PCT/EP2021/065162, filed on Jun. 7, 2021.
Claims priority of application No. 10 2020 115 757.6 (DE), filed on Jun. 15, 2020; and application No. 10 2020 123 493.7 (DE), filed on Sep. 9, 2020.
Prior Publication US 2023/0086841 A1, Mar. 23, 2023
Int. Cl. H02S 50/10 (2014.01); G01R 31/52 (2020.01); H02S 50/00 (2014.01)
CPC H02S 50/10 (2014.12) [G01R 31/52 (2020.01)] 18 Claims
OG exemplary drawing
 
1. A detection device configured to detect a fault current (Ifault) at a PV generator and/or at DC lines of a PV installation assigned to the PV generator, wherein the PV generator has at least a first PV string and a second PV string, which are connected via in each case two DC lines to a PV inverter of the PV installation, wherein the detection device has at least one current transformer and an evaluation circuit connected to the at least one current transformer,
wherein the current transformer comprises a current transformer jointly used by the first PV string and the second PV string, wherein a measurement signal of the jointly used current transformer represents a difference between a first summation current (Isum,1) flowing from the first PV string toward a ground potential (PE) and a second summation current (Isum,2) flowing from the second PV string toward the ground potential (PE), and
wherein the fault current (Ifault), when it occurs, is a part of the first summation current (Isum,1) and/or a part of the second summation current (Isum,2).