Sensitivity analysis for the different types of Partial Discharge sensors related to the measured installation

Transformer (HFCT)Very High Frequency (VHF), and other High Frecuency (HF) types— assessing sensitivity, frequency response, installation complexity, and compatibility. Each sensor excels in different scenarios, depending on defect origin and signal attenuation. For example, Ultra High Frequency (UHF) sensors in joints are more sensitive to local PD sources but less effective if the source is further away. The evaluation covers cable types commonly used by the Spanish Transmission System Operator (TSO), considering insulation, conductor, and sheath sizes, and system voltages. Laboratory tests and field measurements replicate real conditions, supported by accurate cable modelling. A mathematical optimisation model integrates signal attenuation and propagation to define the minimum number and best placement of sensors, balancing accuracy and cost. Preliminary findings show sensor selection and positioning greatly affect PD detection. The research provides guidelines for optimal PD monitoring deployment, helping utilities and TSOs improve reliability, extend cable life, and reduce maintenance costs.