Online and On-site Partial Discharge Measurement of Long Length Power Cables by Using Joints with Integrated PD Sensors

摘要

This contribution investigates integrated capacitive Partial Discharge (PD) sensors in joints. Firstly, the required sensor bandwidth, sensitivity and selectivity are analyzed in context with long length power cable installations and the unavoidable influence of phenomena like attenuation and dispersion on PD pulse propagation along the cable. Secondly, the principle of an integrated capacitive PD sensor is discussed. Furthermore, a model for the integrated capacitive PD sensor is introduced based on material properties and geometry considerations deduced from actual joints. Different parameters like the relative permittivity and the specific resistance per meter are obtained in advance from measurements within the targeted bandwidth. In the next step, an early prototype of a joint with an integrated capacitive PD sensor is built and analyzed in a laboratory setup. Therefore, the transfer function of the integrated capacitive PD sensor is determined using S-Parameter measurements. Subsequently, the modelling approach and simulation results are compared with the obtained measurement data. Based on these findings, the previously developed sensor model is verified. Additionally, the measurement sensitivity of the integrated PD sensor is determined using calibration measurement with an IEC 60270 conform calibrator where the integrated capacitive PD sensor is used as an external coupling capacitor. Finally, the findings in this work will be summarized.