Working conditions
The mixed nature of high-voltage lines makes fault detection and condition monitoring complex, potentially threatening system stability. At the same time, persistent short circuits common in cable sections prevent the use of Automatic Reclosing (ARC). In such cases, the SDO FlexiCDP system—consisting of SDO-Flexi measurement units and the SDO-CFD signal processing and detection controller—is the solution.
The passive, flexible SDO-Flexi optical transformer provides remote current measurement and analysis. They can be installed up to 20 km from the substation. When connected to OPGW, the SDO-Flexi LV sensor is placed below the cable termination, around the insulation, requiring no additional insulation. These sensors are immune to saturation, and their linear characteristics improve fault detection algorithms.
The MU (merging unit) module, installed at the substation and integrated with SDO-CFP, is the only powered component of the system. The transformer connects via standard fiber optic cables. When a fault is detected in the HV line or termination, the controller applies a differential algorithm and issues an SPZ lockout signal.
