Predictive control of a wave to wire energy conversion system — The importance of field weakening

This paper investigates the use of field weakening to improve the electrical power capture of a wave-to-wire wave energy conversion system. The system consists of a Linear Permanent Magnet Generator (LPMG) as the power take off, which produces a physical Power Take Off (PTO) force that is controlled by a machine side Voltage Source Converter (VSC). The electrical power is then maximised using Model Predictive Control (MPC), in accordance with the systems constraints. Field weakening is then included in the systems optimisation, where this paper shows how field weakening can increase the PTO force range, hence, increasing feasibility and decreasing the chances of permanent damage during wave energy periods of low DC-link voltage.