A Real-Time Maximum Power Points Tracking Strategy Consider Power-to-Average Ratio Limiting for Wave Energy Converter

Abstract

Based on the mechanical model of the point absorption Wave Energy Converter (WEC), a real-time complex conjugate (CC) maximum power point tracking (MPPT) control strategy consider power peak-to-average ratio (PAR) limiting under irregular waves is proposed. In the proposed MPPT strategy, the system can not only track the maximum power, but also limit the PAR of the output power to improve the controlled generator's utilization rate. Two parameters, Repot and Xpto, that determine the command current of the PMSG and the PAR, are introduced in the mathematical model of the system to control the system. And they are identified by the Grey Wolf Optimization (GWO) algorithm. During each half cycle of the sea wave, the parameters Rpto and Xpto will be real time updated to satisfy the control strategy. In addition, the system parameters A, Brad and F(ω) related to wave frequency are also calculated by the advanced quantitative wave analysis (AQWA) software. Finally, the proposed strategy is verified by the comparison on the simulation and the experimental results.