Starting from the proof-of-concept fibre optics current sensor (FOCS) developed in EMRP JRP ENG61 FutureGrid (Technology Readiness Level (TRL) 3), this project will progress beyond the state of the art by setting up a non-invasive optimised FOCS sensor as a new wideband reference. The sensors’ non-invasive design, and on-site live connection and measurement procedures, will be made available for use during the calibration phase. This will enable the positioning and measurement time to be minimised, and on-site live calibrations will be made possible with target uncertainties of 0.05 % of the fundamental current at up to 1 kA, thus reaching TRL 6.

The verification of power transformer losses, in the presence of harmonics, requires systematic research with a traceable measurement system. To get a systematic scientific inspection of the influence of harmonics on power transformer efficiency, the existing reference loss measurement systems need to be extended in frequency beyond the present power line frequencies (50 Hz – 60 Hz) to at least 2 kHz.

The techniques for measuring the ratio between the AC and DC resistance of a low loss cable have been established using both electrical and calorimetric measurement systems. This project will go beyond the state of the art for both electrical, and especially calorimetric, methods for skin effect loss
determination in HVAC cables, not only in the presence of the fundamental, but also in presence of harmonics.

This project aims to progress beyond the state of the art by developing innovative techniques for detecting online PD signals within HV cable systems that are subjected to sudden voltage changes like transients (e.g., lightning impulses, pole to ground faults at converter stations), and harmonics. It seeks to establish a reliable method for online PD monitoring (for the detection,classification and localisation of defects or damage before breakdown) in HVDC grids at 100 kV and above, which will be able to distinguish PD from transient noise.