On Cable Selection and Load Detection: a Quantum Sensing exploration with Alliander

The energy transition in the Netherlands is in full swing. Energy network companies such as Alliander are trying the best they can to keep up with all the challenges that the energy transition brings. The most obvious challenge is that the capacity of the energy grid needs to be increased, almost doubled in only ten years of time. This is an enormous task, and grid operators are already behind schedule. Bottlenecks are arising everywhere, slowing down both the energy transition and other societal projects such as the building of housing. The number of bottlenecks will keep increasing if we don’t look at new solutions.
There are many approaches to choose from and experiments to perform to find these new solutions. One of the essential tracks is concerned with increasing the efficiency of current processes related to maintaining the electricity cables within the grid. These cables are often below the surface, which introduces various challenges, two of which we consider in more detail: cable selection and load detection. Both are considered with measuring the magnetic field of a cable to infer properties of the cable. For cable selection, the measurements take place in close proximity to the cable, i.e., in a trench that has been dug open and where now a technician needs to identify the correct cable for their job. For load detection, the measurements take place above ground, so with a larger distance to the cable, and the technician wants to identify how much current is running on the underground cable.
The aim of this project is to investigate the current methodologies and processes related to cable selection and load detection, as well as exploring the applicability of quantum magnetometers to these challenges. Quantum sensing is of interest because certain quantum magnetometer modalities can offer combinations of high sensitivity, vector capability, and bandwidth that may be valuable in specific use cases, e.g., weak signals, or challenging electromagnetic environments with various noise factors. The important questions to answer here are: Where do classical sensors suffice and the limitations are actually somewhere else? And where could quantum sensors add distinct operational value?
This report is structured as follows. We first focus on cable selection in Chapter 2 and use finite element simulations to study magnetic fields close to a cable, leading to practical insights and recommendations as well as a comment on the applicability of quantum sensors. Chapter 3 focuses on load detection, where we model expected magnetic fields further away from the cable and showcase methods to infer current and depth from above ground measurements. We again conclude with summarising our insights and comment on the applicability of quantum magnetometers. Chapter 4 describes the lab and field tests we have conducted with the NV-based quantum magnetometer we develop at TNO in Delft. Finally, we give a summary of the work and combine the different insights gained from desk research and experiments.