With the ever-surging demand to power everything from data centers to growing industries, the need to incorporate new energy sources into our grid has never been more pressing, nor challenging. As new sources of energy like solar and wind farms have come online over the years, a fundamental engineering challenge now grows by the day for grid operators and utilities: How do we manage grid oscillations in aging power systems that are becoming more dynamic?
Currently, operators try to predict all possible sources of energy that could be plugged into a grid, along with all possible oscillation types and operating conditions, during the design phase. However, as more dynamic sources are added to the grid, it becomes harder to predict all potential interactions over the lifetime of the infrastructure. With new technological advancements, unexpected power sources connecting to the system, and unanticipated operating conditions, the grid is at risk of destabilization due to oscillations, as demonstrated in the national-level outages of Spain and Portugal in April 2025.
A simple upgrade to a typical static synchronous compensator (STATCOM) may be the answer to a more stable grid (Figure 1).
Engineered to absorb energy from undesirable oscillations whenever they appear without affecting fundamental-frequency operation, 50Hz or 60Hz depending on the region, the Universal Damping STATCOM (UD-STATCOM), is a patent-pending technology first presented at a CIGRE event in the fall of 2025. CIGRE is a collaborative global community committed to the world’s leading knowledge development program for the creation and sharing of power system expertise.
This UD-STATCOM technology offers a system-level safety net, complementing device-level tuning and reducing the risk of unforeseen interactions, which can lead to grid instability. Coupled with energy storage capabilities, this new technology will significantly improve grid stability and reliability around the world, making it easier and less risky to add renewable energy sources to the grid, preventing power outages and cutting costs of developing power systems for operators and utilities.
How the UD-STATCOM Works
The simplest analogy for this new technology is a shunt resistor that absorbs energy at all frequencies except for the fundamental frequency. It is well known that resistance improves system damping by absorbing energy from oscillations. The UD-STATCOM controller monitors the AC voltage for any oscillations other than the fundamental frequency. If any undesirable oscillation is detected in voltage, the UD-STATCOM current is ordered via integrated software to change proportionately.
Since the UD-STATCOM voltage and current are proportional to undesirable oscillations, it acts similarly to a resistor and absorbs energy from the oscillations, therefore providing positive damping. However, the absorbed energy is not dissipated, it is returned to the system at fundamental frequency.
It is important to note that undesirable oscillations do not occur very often. Therefore, under normal conditions the UD-STATCOM can operate as a regular STATCOM, providing reactive power and voltage support to the system. Once an oscillation is detected, it can use part of its capacity for damping the oscillation. As such, adding the universal damping feature to a STATCOM does not require an increase in voltage and current ratings of the main circuit components. In other words, the universal damping feature is achieved by modifying the controls of a regular STATCOM.
The technology provides positive damping to a wide range of oscillations, regardless of the cause of the oscillation. This reduces the risk of dynamic instability in the system and considerably improves system resilience.
To test the effectiveness of this technology, Dr. Mojtaba Mohaddes, senior technical manager at Ramboll and the inventor of the technology, conducted an electromagnetic transient, or EMT, simulation of a 200-MW wind farm connected to the rest of the system radially via a single 230kV transmission line with series compensation at the midpoint. The line was 400 kilometers (about 250 miles) long, and the compensation level was set at 50%. He then applied a 10% change in wind speed, which created instability.
With the new technology in place prior to the oscillation, models showed that shortly after a wind speed change, there was a small oscillation that caused the UD-STATCOM to inject current into the system and absorb some power. This successfully suppressed the oscillation, and the wind farm remained stable for the remainder of the simulation. Dr. Mohaddes also ran a second simulation where the UD-STATCOM was enabled 0.5 seconds after the wind speed change. In this case, the oscillations were quickly suppressed as soon as the UD-STATCOM was enabled.
The Future of Grid Resilience
Grid operators and utilities are looking for ways to meet escalating climate change challenges and bolster infrastructure resilience. Yet the scale and cost of updating aging infrastructure continue to rise, often requiring billions of dollars and years of planning.
With this oscillation-damping technology, several facets of resilience become achievable–reliability, agility, and scale–at a comparably significantly lower cost than a full infrastructure upgrade. By increasing reliability of power access, this technology can help countries achieve their sustainability and renewable energy goals without worrying about fluctuations in stability and efficiency that come with dynamic power sources.
As power systems evolve, this capability will be essential to ensure that the grid can keep pace with current and future needs. Original equipment manufacturers, utilities, and investors are currently working to bring this technology to market and help deploy this innovation worldwide.
—Darek Letkiewicz is the director of Strategy and Growth for Energy Systems at Ramboll in the Americas. Ramboll is a global architecture, engineering, and consultancy company founded in Denmark in 1945 with the mission to create sustainable societies where people and nature flourish.
