In the heart of South Korea, Jeju Island stands as a beacon of renewable energy integration, but with great power comes great responsibility—especially when it comes to maintaining grid stability. As the island ramps up its solar and wind capacity, researchers are racing to ensure that the power system can handle the influx of intermittent energy sources. Enter Sungryeol Kim, an electrical engineering professor at Gachon University, who has developed a groundbreaking method to assess transient stability in real-time, a critical factor in preventing blackouts and ensuring a smooth energy transition.
Kim’s work, published in the journal Energies, focuses on the Jeju power system, which is uniquely positioned as an independent grid connected to the mainland via high-voltage direct current (HVDC) lines. This isolation makes it an ideal testbed for studying the impacts of high renewable energy penetration. “Jeju Island is the most active area in Korea for the expansion and supply of renewable energy,” Kim explains. “However, the load of the system is small, and it is an independent system linked to HVDC with land.”
The core of Kim’s approach lies in estimating the Thevenin impedance—a measure of the system’s electrical resistance—using real-time data from Phasor Measurement Units (PMUs). These devices, installed at key points in the grid, provide high-resolution measurements of voltage and current, allowing for accurate monitoring of the system’s state. By plotting a power-phase angle curve and applying an improved equal-area method, Kim’s technique can quickly assess transient stability, a crucial factor in preventing cascading failures and blackouts.
The implications for the energy sector are significant. As renewable energy sources like solar and wind become more prevalent, traditional stability assessment methods struggle to keep up. These methods often rely on extensive offline simulations and detailed system modeling, which can be time-consuming and computationally intensive. Kim’s real-time approach, on the other hand, offers a more practical solution for modern grids with high renewable energy penetration.
“Unexpected situations can occur in a power system, such as sudden increases in load, track drops, or generator drops,” Kim warns. “Stability can be interpreted from several perspectives. Among them, the stability interpretation that is typically considered is phase-angle stability.” By providing a stability ranking rather than an exact critical clearing time, Kim’s Transient Stability Discrimination Index (TSDI) offers a computationally efficient tool for real-time grid operations.
The commercial impacts of this research are far-reaching. As energy companies strive to meet decarbonization goals, they must also ensure that their grids remain stable and reliable. Kim’s method could help prevent costly outages and improve the overall efficiency of power systems. Moreover, as the demand for renewable energy continues to grow, so too will the need for innovative solutions to integrate these sources into the grid.
Looking ahead, Kim envisions a future where his method is integrated into control center applications, providing operators with real-time stability assessments. “In the future, a method will be presented for determining changes in transient stability due to continuous renewable energy connections,” he says. This could pave the way for more ambitious renewable energy targets and a more resilient power system.
As the energy sector continues to evolve, researchers like Kim are at the forefront of developing the tools and technologies needed to support a sustainable future. His work, published in Energies, is a testament to the power of innovation in addressing the challenges of our time. With real-time stability assessment, the path to a greener grid is looking brighter than ever.
