Final Design

Background

Floating offshore wind turbines are a promising frontier in renewable energy, offering access to deeper waters where wind is stronger and more consistent. However, a major technical challenge remains: stabilization. Unlike land-based or fixed-bottom turbines, floating platforms are constantly subjected to wave and wind disturbances, which can induce dangerous tilting and reduce power generation efficiency. Traditional solutions rely on passive ballast systems that lack responsiveness in dynamic conditions and require costly manual intervention.

Historically, wind energy technology has seen transformative improvements through the integration of active control systems—such as yaw and pitch control—to optimize efficiency and safety. Our project continues this trend by developing a novel active ballast control system to stabilize semi-submersible wind turbine platforms in real-time.

Project Objective

This project aims to design, build, and validate a low-cost, scaled prototype of an autonomously stabilizing offshore wind platform. The testbed uses modulating ballasts actuated by linear pistons to shift the platform’s center of mass and center of buoyancy, thereby correcting for angular disturbances induced by simulated wind forces. By proving control strategies on a smaller scale, the system provides a valuable research platform for developing full-scale implementations—while maintaining a total hardware cost under $300.

Design Solution

Our platform consists of three radially distributed ballasts surrounding a central spar. Each ballast is independently controlled by a linear actuator-driven piston, allowing for real-time water intake and expulsion. These motions are guided by angular data collected from an inertial measurement unit (IMU) housed in the turbine nacelle.

A PID control algorithm processes sensor data to dynamically stabilize the platform’s pitch and roll. Control electronics are housed inside the central spar and include Arduinos, a battery pack, and signal routing. All structural components are 3D-printed using ASA plastic and sealed for water resistance.

To ensure dynamic similarity with real-world systems, the entire prototype is Froude-scaled based on the 15 MW UMaine VolturnUS-S reference turbine. A dual-shell mast was developed to simultaneously match mass, stiffness, and geometric scaling requirements.