Velocity Zero Crossing Detection-Based Variablestep Perturbation and Observation for Wave Power Generation System

Based on the mathematical model of the direct-drive wave generator system, while combining the potential energy theory of hydrodynamics, the relationship among the velocity, electromagnetic force, electromagnetic power, and damping coefficient of the permanent magnet linear generator is analyzed in the frequency domain. As a result, the condition that the electromagnetic power reaches the maximum point is obtained, and the curves of the maximum power point and instantaneous power with respect to the damping coefficient are performed. According to the characteristics of wave period variation, aiming at the phenomenon that the perturbation period of traditional perturbation observation method is difficult to select and the perturbation step size error caused by instantaneous power ripple error, a variable-step size velocity zero-crossing detection-based perturbation observation method is proposed to realize maximum power point tracking. Simulation results demonstrate that this method is a fast convergence and high accuracy rectifier side control strategy for direct-drive power generation system.