The portable combined CDS from HDW Electronics is used as a universal dielectric diagnostic system on PE/XLPE insulated cables as well as paper-insulated cables worldwide. It combines the known methods of isothermal relaxation current measurement (IRC-analysis) and voltage return method (RVM-analysis) for aging and deterioration diagnostics. Due to the low charging voltage of the measurement, the CDS works absolutely non destructive.
The diagnosis of PE/XLPE cables applies for evaluation of an IRC measurement a software-module with neuro-fuzzy-extension. The intelligent multistage evaluation software take into consideration the special construction criteria of the test object and categorizes the condition of the test object, including an anticipated maximum residual voltage level.
The software includes a database with automatic research for calculation of voltage withstand prognosis values according to data material of the standard DIN VDE 0276 as well as the protocolling of the diagnostic results.
The RVM cable evaluation is done using proven standardized factors and threshold values.
The opening of the electric power markets and new forms of asset management lead to the need to increase life cycles of installed energy components and to be more economic regarding existing underground installations. Using integral diagnostics, the cable operator has a valuable tool for non-destructive analysis of the cable network. This condition based maintenance makes planning easier whether to repair or replace an existing cable.