RISE works together with the Swedish transmission system operator Svenska Kraftnät to improve measurements in the transmission grid. Through accredited control, continuous monitoring and development of measurement methods, the grid's reliability is ensured.
The transmission grid transports electricity produced in generation plants to the regional and local power grids. Svenska Kraftnät is responsible for the transmission grid, which includes roughly 17,000 kilometers of lines and approximately 200 substations throughout the country.
“We are constantly measuring the amount of electricity flowing into and out of the network to ensure correct billing. It’s important to maintain the different actor’s trust in the grid. Both the electricity producer and consumer want correct billing, and that requires accurate measurements”, says Anders Lindskog, measurement technology specialist at Svenska Kraftnät.
Both the electricity producer and consumer want correct billing, and that requires accurate measurements
Accredited controls and continuous monitoring
Inspections of all energy measurement systems in the substations are carried out every six years by an accredited control body, according to legal requirements and regulations. Currently, RISE performs these inspections on site in the substations. The measuring instruments are verified and calibrated, and adjustments are made if any errors are detected.
“But even if the inspections carried out by RISE is of the highest quality, things can happen in the grid stations between the inspections. A component may break the next day, and then it is several years until the next inspection. To address this, we have collaborated with RISE for a long time to develop continuous monitoring of our measurements”, says Anders Lindskog.
The financial consequences can be substantial if something is wrong. Small errors such as 0.1 percent can result in hundreds of thousands SEK in billing error per month for a larger measuring point.
“The legal requirements are 0.5 percent measurement accuracy, but we always strive to exceed the legal requirements, not only to avoid erroneous debits but also to build and maintain the market´s trust in the grid”, says Anders Lindskog.
First project in 2013
Modern measuring instruments makes it possible to measure more than just electricity in and electricity out, and to collect the measurements in real time. The first joint research project between RISE and Svenska Kraftnät to develop methods to utilize these measurements started already in 2013.
“We have now implemented the methods for continuous monitoring that we developed for daily use. This not only ensures the quality of the measurements but also aids in interpreting what they mean, enabling informed decisions based on the measurements. With continuous monitoring, we can identify errors when they occur, errors that could otherwise go unnoticed until a physical inspection, up to six years later, says Niklas Eriksson, senior researcher at RISE and continues:
“We can spot and fix a variety of minor errors that previously could go undetected. For instance, a blown fuse might cause a minor error, which would have been difficult to detect even during a physical inspection.
Anders Lindskog at Svenska Kraftnät sees many advantages in collaborating with RISE.
“While the accredited inspection is undeniably independent, it’s also important in our other collaborations that RISE operates as an independent party. RISE also has the expertise and knowledge we require to develop methods and working processes”, he says.
Can we measure too much?
“Measurements cost money, but every time we start to measure more accurately, we always find something to develop and improve. We have only just begun to see the benefits of this”, says Anders Lindskog.
