Abstract: This disclosure relates to a method of and a system for fault detection and localization of a fault in a DC-system comprising multiple serially connected DC-sources. The method may comprise an act of connecting a test apparatus to at least one terminal of the DC-system and to DC-system ground. The method encompasses at least one repetition of an act of applying a test AC-signal to one terminal of the DC-system, an act of detecting the response AC-signal to the test AC-signal on either one terminal alone and/or on DC-system ground; and an act of comparing the test AC signal with the response AC-signal to detect a fault and the location of the fault in the DC-system. The system comprises a fault detection and localization apparatus configured to perform the method disclosed.

Abstract: This disclosure relates to a method of and a system for fault detection and localisation of a fault in a DC-system comprising multiple serially connected DC-sources. The method may comprise an act of connecting a test apparatus to at least one terminal of the DC-system and to DC-system ground. The method encompasses at least one repetition of an act of applying a test AC-signal to one terminal of the DC-system, an act of detecting the response AC-signal to the test AC-signal on either one terminal alone and/or on DC-system ground; and an act of comparing the test AC signal with the response AC-signal to detect a fault and the location of the fault in the DC-system. The system comprises a fault detection and localisation apparatus configured to perform the method disclosed.

Abstract: There is provided a method for fault diagnosis on a solar module in which electrical potentials are checked within the solar module to provide the possibility for carrying out the fault diagnosis even when the solar module is not exposed to sun light. Specifically the solar cell module is excited by both a DCBIAS and an AC voltage over a wide frequency range, and the impedance of the solar cell module is measured as a function of the frequency response. There is also provided an embodiment, wherein time domain reflectometry (TDR) is used in combination with the DC BIAS and AC voltage based fault diagnosis. Based on the method safety operations can be carried out as a part of the integrated electric functionality.