Dual multivector model predictive control for the power converters of a floating OWC WEC

Abstract

Oscillating Water Column (OWC) is one of the most well-known wave energy converter (WEC). Typically, OWCs are installed in rocky shores or in custom-built breakwaters. However, since the wave profile is more favorable in an open sea, it can also be installed in a point absorber in order to increase the energy extraction. This paper presents the development of a new dual Multivector Model Predictive Control (MMPC) for the power converters of a floating OWC WEC. The fast dynamic response featured by the proposed MMPC has proven to be very suitable to deal with the highly variable torque and velocity of the turbines present in this type of WECs, achieving an outstanding tracking of the references. Besides, the dual MMPC provides high-quality current to the electric generator and to the grid. The performance of the MMPC for floating OWC WEC has been tested in the laboratory by implementing the mathematical model of the complete OWC WEC installed on a buoy, in the real-time controller of an emulator. The model is based on Thevenin equivalent theorem to simplify the calculation of the force generated by the power take-off (PTO) system.