Full-scale measurement of electric-power quality at Tidaholms Energi

Tidaholms Energi (DSO) is making a comprehensive investment in measuring power quality and detecting disturbances. The benefits include higher security of supply, scope for proactive maintenance and better grid information.

“Power quality measurement is becoming increasingly important because it enables us to provide a good product with a high security of supply,” says Magnus Sjögren, Grid Manager, Tidaholms Energi. We envisage being much more proactive than we are today. Instead of customers having to call in and tell us something is wrong, we should plan our own downtime and inform the affected customers in advance.

Today’s rapid technological development with an increasingly keener focus on sustainability makes new demands on the electricity grid. Electricity consumption is generally increasing, partly due a larger number of electric vehicles, which can also cause sharp power spikes. At the same time, small-scale electricity production, primarily from wind and solar, is being added to the grid.

“We’re transitioning from a few major sources of power to more small-scale and dispersed electricity generation,” Magnus Sjögren says. “These comprehensive changes will take place within a short time frame. Systematic power quality measurement, analysis and follow-up will help us manage this transition and prepare for future changeovers to new technology at the same time.”

Strategic partnership with Metrum

Tidaholms Energi embarked on strategic collaboration with Metrum in 2020. So far, a number of Metrum’s PQX3-FR instruments have been installed at two of the utility’s substations, and yet another substation will be equipped with this capacity. At the substations, Tidaholms Energi measures all outgoing medium-voltage lines and input points from the feeding grid. In order to establish comprehensive metering, the utility has also started measuring power quality in low-voltage grids by installing Metrum SC at certain selected substations.

In the long term, Tidaholms Energi wants to measure all the power grid’s input points and medium-voltage lines to be able to monitor energy and power-quality profiles as well as disturbances in real time, but also to be able to follow up on long-term trends and variations. The power company uses Metrum’s regular database system PQ Controller DB, and its Power Monitor and PQ4Cast systems for analysis and visualisation purposes as these enhance a proactive approach by alerting well before various power quality parameters reach unwanted levels.

“More advanced measurement enables us to detect faults before they result in disturbances,” Magnus Sjögren says. “Examples of these are cable faults or tree branches accidently lying on an overhead line. Having this information enables us to redirect and supply power from a different direction so customers aren’t affected as we begin working to rectify the fault.”

Metrum’s measuring instruments can also indicate other types of faults. Over the summer, Tidaholms Energi’s new system detected that the source of a sudden surge in reactive power came from a defectively connected customer facility. This enabled the company to avoid having to pay additional charges for the feeding grid.

Automated reports

Metrum’s system provides different levels of analysis and visualisation, ranging from simplified reports showing green or red (“everything is ok” or “something is wrong”) to detailed information about what’s going on in the power grid. The various meters also collect data in one and the same system, which facilitates overview and analysis.

“We can generate reports that are understandable for our customers,” Magnus Sjögren says. “This makes it easier for our employees to respond to questions and complaints, because we simply have better information and this information can be clearly depicted as well. At the same time, our technicians can produce more detailed reports that give them the proper prerequisites for following up on deviations and problems.”

Reduced costs and enhanced customer value

The financial incentives for investing in power quality measurement derive from Tidaholms Energi’s expectations of being able to chart and reduce energy losses in the grid. Thanks to the broad implementation of meters at different levels and locations within the grid, the utility can analyse variations in energy and power profiles in different parts of the grid and at different times of the year. Together with the rest of the power quality measurement, this enhances the utility’s understanding of how local phenomena in individual parts of the electrical grid can increase total costs.

The use of the Power Monitor and PQ Forecast software makes it possible to predict unwanted fluctuations, such as excessively low or high voltage levels or power spikes, well in advance, making it possible to take the necessary steps to avoid future problems. For example, this may mean being able to start backup power plants in time to avoid power spikes that can increase costs from having to buy subscribed power from a regional grid owner.

“There is no incentive to increase the customers’ rates, however,” Magnus Sjögren says. “We want to use metering to reduce our costs and be able to keep our competitive prices. As a municipal energy utility, an important part of our mission is to help make Tidaholms Energi attractive to residents and businesses alike. Security of supply and reasonable electricity prices are important parameters in this respect.”

In the slightly longer term, Tidaholms Energi wants to interconnect advanced power-quality measurement with the usual billing metering to be able to collect and visualise all the data available in the same system. Metrum is a valued partner in these continued development efforts.

“Metrum has excellent knowledge of measurement and the problems that can arise in various operating situations,” Magnus Sjögren says. “We have excellent support and added value in this collaboration. Their roadmap for how they want to develop their products and solutions also conforms to what we want to do. They go from being a traditional measurement company to starting to bring in AI to enhance customer value.”

Results of the collaboration
  • and improved decision-making basis for taking action
  • Assistance in avoiding excessive power tariffs
  • Effective charting of power-quality deviations
  • Improved information about power quality when connecting renewable energy
  • Strategic preparations for the future’s smart power grids

Tidaholms Energi (DSO) has around 7,000 electricity customers. Operations also include urban power grids, district heating, energy trading and a municipal housing company.

Read more about Tidaholms Energi