New sensor technology can predict faults in the power grid
In a new research project at the Faculty of Engineering at SDU, researchers and private partners will develop sensors that can be attached on the outside of power cables and detect if there is something wrong with the cables before they fail. This can lead to massive CO2 reductions and save money.
Electric cars, heat pumps, solar panels, power-to-X, electric ovens and boilers in the industry...
The extensive electrification of society, which is currently underway, is necessary to power the green transition. But it also requires a significant expansion and ongoing maintenance of the aging Danish power grid.
Many power cables in Denmark are from the 1960s and 1970s, and according to utility companies, more and more faults are starting to occur.
Therefore, new and smart ways are needed to monitor and maintain the power grid. This is exactly what the PowerGridOptimiser research project is about.
Researchers from the Faculty of Engineering at the University of Southern Denmark have teamed up with the company ReMoni, KM Telecom, and the utility company TREFOR.
Together, they will develop a series of so-called clamp-on sensors that can be attached outside the power cables and monitor the state of the power grid.
Compared to current solutions, the clamp-on sensors will make it significantly easier and cheaper, explains professor Hamid Reza Shaker from SDU.
- Today, you have to cut the cables and attach measuring devices to measure how they are doing. It almost goes without saying that this is extremely expensive and cumbersome, he says.
Two big problems
When the sensors are fully developed, they will be able to solve two major problems and potentially save tons of CO2 emissions, says Bo Eskerod Madsen, CEO of ReMoni.
- The sensors will be able to monitor which cables are worn and need to be replaced. Right now, only about 10% of the cables fail, so we should be able to let the remaining 90% stay in the ground. The challenge lies in knowing which ones are good and which ones are not.
Today, it is easy to over-replace power cables because we do not have enough information about their condition, the CEO explains.
- But the sensors can also monitor what are called harmonics. These occur in faulty installations, and it is becoming an increasing problem. It burdens the power grid and damages transformer stations, leading to a lot of waste, says Bo Eskerod Madsen from ReMoni.
- Globally, energy loss due to harmonics equals France's entire electricity consumption.
Benefits for consumers
For utility companies, the sensors will be a great help both in maintaining the current cables and in planning the expansion of the power grid.
And this will ultimately benefit consumers, says Louise Carina Jensen, planning engineer at TREFOR.
- Today, we hardly measure on the power grid because it is so expensive. But if we can lower the cost of measurements, it will mean that we can replace and repair power cables without consumers experiencing interruptions, she explains.
Because electricity consumption is expected to rise drastically in the coming years, there is also a need to replace some cables with larger dimensions. The new technology will also be helpful in this work.
- We cannot replace all cables at once, so there is a lot of planning work ahead. And if we can measure the cables and predict when they are worn and failures occur, we can also allow ourselves to let old cables remain in the ground longer. It's a bit like if you have an old water pipe at home. If you are told in advance when it will burst, you dare to keep it longer, says Louise Carina Jensen.
Needle in a haystack
The new technology will build on sensors that ReMoni has already developed.
Additionally, the software and models are needed to analyze the data from the sensors and detect if something is wrong. This is what researchers from SDU’s Center for Energy Informatics and Centre for Industrial Electronics will work on.
According to Professor Hamid Reza Shaker, it is not an easy task.
- It's a bit like finding a needle in a haystack. You must sort through all the signals that the sensors pick up, and many of them have nothing to do with the cables being worn out.
Specifically, they need to develop models that can detect when there are small leaks in the cable insulation, which fills with water, gets burned away, and sends small electric charges into the surrounding ground.
- We call it partial discharge, and the process is quite gradual. So, if we can detect the signals early in the process, we will be able to detect the problem before the cable fails.
Om projektet
PowerGridOptimiser is a 3-year research project funded by the Danish Energy Agency's development fund EUDP.
The partners in the project are ReMoni, University of Southern Denmark, TREFOR, and KM Telecom.
The goal is to develop new clamp-on sensors that can make the maintenance of the power grid better and easier and solve two major problems:
· Over-replacement of cables because it is not known which ones are worn and which are fine. Globally, nearly 100 billion euros are spent on cable replacements, responsible for 19.2 billion kilos of CO2-e.
· Harmonic currents that annually cause an energy loss of 600 billion kWh, corresponding to 285 billion kilos of CO2 equivalents.
The sensors will also be helpful for the utility companies in the planning of the expansion of the power grid.