Technology is being developed to prevent damage to wind turbines, which are more vulnerable to lightning strikes in winter, and it is expected to contribute to the expansion of renewable energy by increasing the stability and efficiency of wind turbines.

The Korea Electrotechnology Research Institute (KERI) announced on the 16th that Dr. Woo Jeong-min's team at the Electric Environment Research Center developed the world's first technology that can prevent damage from positive lightning, which frequently occurs at offshore wind farms during the winter.

Lightning is divided into positive and negative polarity, just as voltage has positive and negative poles.

Positive lightning occurs when clouds are positively charged and the ground is negatively charged. It has a lower probability of occurrence than negative lightning, but the current is very strong. Positive lightning occurs mainly in winter, when the cloud altitude decreases.

Recently, with the increase in demand for renewable energy, the construction of wind power plants is rapidly increasing. In particular, in Korea, many large wind turbines specialized for low-wind environments are being built in the sea.

On the other hand, offshore wind power is highly vulnerable to lightning strikes due to its tall tower structure. Blade damage caused by lightning can cause significant damage to wind turbines, resulting in downtime and repair costs.

Dr. Woo Jung-min's team has developed a new design method to protect wind turbine blades from positive lightning strikes.

Although existing blades have lightning protection elements to minimize lightning damage, their protective effect against positive lightning was low.

To solve this, the team thoroughly analyzed various conditions, rotation angles of the blades, materials, etc.

As a result, it was confirmed that positive lightning avoids the existing lightning strike and strikes the edge next to the blade.

The research team created a scale model and repeatedly performed artificial lightning experiments using a high-resolution camera.

This led to the development of a new design method that optimally positions the air-termination unit at the blade edge.

This method was confirmed to be able to minimize damage by controlling the charge distribution of positive lightning.

Dr. Woo Jung-min said, “We are the only organization in the world that has designed and experimentally verified countermeasures against positive lightning strikes on wind turbine blades,” and “This research will contribute to the expansion of renewable energy by increasing the stability and efficiency of wind power generators.”

This study was published in 'Results in Engineering', a top 5% international academic journal in the field of renewable energy, and was also contributed to the official journal of the International Council on Large Electric Grids (CIGRE).

KERI plans to secure additional experimental data by applying the design method to actual-scale wind turbine blades and promote related patent registration and technology transfer to companies. In the future, the scope of research will be expanded to areas vulnerable to lightning strikes, such as high-rise buildings, communication towers, and marine structures, in addition to wind power.

This study was conducted with the support of the ‘Development of Platform Technology for Lightning Countermeasures for Large-Scale Offshore Wind Power Plants’ project by KERI, a government-funded research institute under the National Research Council of Science and Technology of the Ministry of Science and ICT, and the Korea Institute of Energy Technology Evaluation and Planning.