Research on an improved model predictive current control for direct-drive wave energy converters with linear generators

This paper deals with the current control strategy of a permanent magnet linear generator (PMLG) for a direct-drive wave energy converter (DDWEC). As the mover is in a linear reciprocating motion, the reference of the controller of the generator is dynamic fluctuations with the mover movement under maximum power point tracking (MPPT) conditions. Therefore, the dynamic requirements of the controller become higher. To increase dynamic control performance, an improved model predictive current control (IMPCC) strategy is proposed here. Through a three-step cascaded optimization algorithm, the target voltage vector is optimized from the three dimensions of the sector of the voltage vector, the angle of the voltage vector and the length of the voltage vector. The target voltage vector is output to the three-phase rectifier by using SVPWM to complete the entire control process. Simulation and experimental results show that the proposed control strategy effectively reduces the current ripple and the vibration of PMLG and improves the stability of DDWEC.