Development of a simple power controller for horizontal-axis standalone tidal current energy generation system

Tidal current energy, which is one of the most predictable forms of ocean renewable energy, is mainly utilised for electricity generation. This paper presents a simple control strategy for an optimal extraction of output power from a horizontal-axis variable speed tidal current turbine generation system with a permanent magnet synchronous generator (PMSG) that is driven directly by a fixed-pitch turbine. The maximum power point tracker (MPPT) extracts the turbine's maximum power from cut-in current velocity to rated value by measuring only dc link parameters. Together with a dc-dc converter PWM controller, MPPT variable-step searching algorithm is modelled and simulated using Matlab/Simulink software. The simulation results indicate that the variable-step searching algorithm can effectively track the maximum power point without collecting the data of tidal current velocity or rotor speed. Such MPPT controller provides a simple and practical method for the maximum power control of standalone tidal current energy conversion system. Copyright © 2017 Inderscience Enterprises Ltd.