Variable speed constant frequency tidal current energy generation and control strategy for maximum power point tracking and grid connection

This paper proposes a variable speed constant frequency tidal current generation system and its control strategy. An advantage MPPT (Maximum Power Point Tracking) control method by seeking the optimal duty cycle of boost converter is presented, maximum energy capture from tidal current is achieved without using hydro turbine characteristic at various tidal current velocity and measure the tidal current velocity and the rotational speed of tidal current turbine. The mathematical model of the grid-connected inverter is built, and the SVPWM (Space Vector Pulse Width Modulation) based inverter and its control strategy for supply side is also presented. The adjustability of the power factor is realized based on current close loop and grid voltage vector oriented control, so the active power and reactive power delivered to the grid can be controlled independently. Simulation results demonstrate the efficiency and correctness of the proposed scheme.