Control Strategy for Array Buoy Type Wave Energy Converters' Power Conversion

Abstract

In order to solve the problem of complex inner‐loop control structure, difficult debugging of control parameters and poor anti‐interference ability in the double PI power conversion control method of array buoy type wave energy converter, this article proposes a power conversion control strategy in which the one step delay compensation model predictive current control strategy is proposed for the machine side rectifier and the three closed‐loop control structure with PI voltage outer‐loop, quasi‐proportional resonant (QPR) current inner‐loop and proportional capacitor current inner‐loop is proposed for the grid‐side LCL inverter. In addition, this article proposes a graded power generation scheme for a single oscillating buoy and two power generation branches, which aims to address the issue of a restricted safe working pressure range for the accumulator in the single buoy and single power generation branch mode. Based on the mathematical model of the system's key components, the MATLAB/Simulink program is applied for modeling and simulation. The results indicate that the recommended graded power generation scheme and power conversion control mechanism may accomplish stable operation of the system under three diverse wave conditions, showing the scheme's practicality. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.