Stand-alone system for Oscillating Water columns: Design and numerical simulation

Wave energy is an abundant renewable energy source with great potential to add to the energy mix and reduce carbon emissions. There are many wave energy devices, and the technology has a relatively low TRL compared to other renewable energy technologies. To address this issue, the sector should move towards intensive testing, not only in laboratories but focusing on testing in real-world conditions. Utility-scale projects involve large amounts of capital. A possible solution with a considerably lower investment is the use of small devices that, although not intended to supply the utility grid, can test the technology and at the same time collect important information on operation and maintenance, thereby reducing the associated risk. The present paper focuses on the design and simulation of the power conversion and control system for a stand-alone floating oscillating water column device equipped with a biradial turbine. This work models and analyzes the design and control of the power converter system to enable effective control of the generator, maximizing the energy output under variable flow operating conditions. Simulations are conducted to evaluate the system's behaviour under different sea states, representative of the conditions predicted for the buoy deployment in the Azores, Portugal.