3D SSTDR Digital Twin of an Electrical Cable: A First Glance

Nuclear power plant (NPP) electrical cables are essential components of power, control, and instrumentation systems. Environmental stressors, such as heat and radiation, can reduce electrical cable service life. Electrical reflectometry methods are commonly employed to identify and locate cable degradation. However, most reflectometry methods require cables to be de-energized and de-terminated prior to testing. Spread spectrum time domain reflectometry (SSTDR) has been identified as a potential solution to these issues but additional work is needed to understand the influence of a wide variety of fault types on SSTDR response. In this work, we explore development a fully 3D SSTDR digital twin to predict cable degradation. A typical 3-conductor low-voltage electrical cable was selected for evaluation and 20-m of cable was simulated within COMSOL Multiphysics<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup>, Insulation damage was induced over 1-m through scaling of empirically-derived permittivity. The results demonstrate the feasibility of the approach to accurately detecting cable damage but additional work is needed to reduce noise due to the connection.