Advanced Optical Fiber Sensor Enhances Wind Turbine Vibration Monitoring

IoT vibration sensors for wind turbines are essential © JohanSwanepoel-chronicles-stock.adobe.com

Wind energy is rapidly growing as a sustainable alternative to fossil fuels, with increasing investments worldwide. However, wind turbines operate in harsh environments, making them susceptible to structural failures. Among these, vibrations in the wind turbine tower serve as a critical early warning sign of potential mechanical issues. Traditional electrical vibration sensors face challenges such as power supply limitations and electromagnetic interference, making them less effective for long-term monitoring (1).

A research team comprising Yuliang Jia, Jia-Wei Zhang, Zifan Ye, Lin Fu, Bin Zhang, and Fouad Belhora from institutions including Xi’an University of Technology, Chongqing Electric Power College, State Grid Xinjiang Electric Power Co., Shandong University, and Chouaib Doukkali University has designed and tested an innovative optical fiber vibration sensor (OFVS). Their findings, published in Sensors and Actuators A: Physical, demonstrate the sensor’s ability to improve wind turbine vibration detection significantly (1).

Development of the Fabry-Perot Optical Fiber Sensor

The newly designed OFVS operates on the Fabry-Perot interference principle, ensuring high sensitivity and strong resistance to environmental disturbances. The sensor consists of a circular diaphragm, a pedestal, and a single-mode fiber, forming an extrinsic Fabry-Perot interferometer (EFPI). A central mass block on the diaphragm acts as the key vibration-sensitive element.

The team conducted mechanical simulations to validate the sensor’s design and ensure optimal performance. The experimental results revealed a resonant frequency of 223 Hz, an output sensitivity of 122.22 mV/m·s² at 10 Hz, and minimal horizontal output interference below 6%. These characteristics enable the sensor to effectively detect low-frequency vibrations, a crucial parameter in wind turbine tower monitoring (1,2).

Advantages Over Traditional Sensors

One of the major drawbacks of conventional electrical vibration sensors is their susceptibility to electromagnetic interference, which can distort readings and lead to unreliable data. Additionally, these sensors require a continuous power source, adding complexity to remote wind turbine operations. In contrast, the new OFVS is passive, meaning it does not require an external power source, making it an ideal solution for remote and challenging environments.

Compared to laser-based sensors, which offer high accuracy but are costly and require specialized installation, the Fabry-Perot OFVS provides a cost-effective and scalable alternative. Its compact structure and resistance to extreme weather conditions further enhance its suitability for real-world deployment (1,2).

Experimental Validation and Findings

To verify the sensor’s performance, the researchers conducted rigorous testing using a sinusoidal signal generator, power amplifier, and vibration exciter. The experiments demonstrated a favorable amplitude-frequency response in the range of 10–150 Hz, making the sensor suitable for detecting the low-frequency vibrations commonly associated with wind turbine tower stress.

The sensor’s diaphragm-type cantilever beam structure was engineered to provide enhanced sensitivity while reducing horizontal interference. Six adjustable notches on three equal-strength beams allow for precise tuning of the resonant frequency, enabling customization for various environmental conditions and structural monitoring needs (1).

Potential for IoT Integration and Future Applications

The study highlights the potential of integrating the Fabry-Perot OFVS into IoT-based monitoring systems for real-time structural health analysis. With the increasing digitalization of wind energy infrastructure, the sensor could play a key role in predictive maintenance strategies, reducing downtime and improving turbine lifespan (1).

Beyond wind turbines, the technology could be adapted for other structural monitoring applications, including bridges, buildings, and aerospace components. The researchers suggest further exploration into enhancing sensitivity and expanding the sensor’s application range to maximize its impact (1).

The research led by Jia and colleagues presents a significant advancement in wind turbine monitoring technology. By leveraging optical fiber sensing and Fabry-Perot interference, the new sensor offers high sensitivity, passive operation, and strong resistance to electromagnetic interference—key advantages over traditional vibration sensors. With further development and IoT integration, this innovation has the potential to transform how wind turbine structures are monitored, ensuring safer and more efficient renewable energy production.

References

(1) Jia, Y.; Zhang, J. W.; Ye, Z.; Fu, L.; Zhang, B.; Belhora, F. Low-Frequency Vibration Monitoring of Wind Turbine Tower Based on Optical Fiber Sensor and Its Potential for Internet of Things. Sens. Actuators, A 2024, 379, 115891. DOI: 10.1016/j.sna.2024.115891

(2) Wang, D.; Wu, Y.; Song, Y.; Wang, Y.; Zhu, L. High-Sensitivity Fiber Optic Acceleration Sensor Based on Fabry-Perot Interferometer. Opt. Fiber Technol. 2022, 72, 102989. DOI: 10.1016/j.yofte.2022.102989