Adaptive backstepping based maximum power point tracking control for a variable speed marine current energy conversion system

This paper presents a novel maximum power point tracking (MPPT) control strategy for a small scale variable speed permanent magnet synchronous generator (PMSG) based marine current energy conversion system. A nonlinear control algorithm for the load side converter to extract maximum power has been proposed to adequately deal with the inherent nonlinearities in the energy conversion system. The proposed control strategy does not require any flow sensors and also does not need the parameters of a PMSG. A Lyapunov based online estimation approach is used to continually estimate the input voltage and the output load resistance of the converter. Detailed simulation results of the proposed nonlinear controller namely adaptive backstepping are presented and fully analyzed. Simulation results demonstrate that the proposed nonlinear controller can incessantly extract maximum power from the ocean current at various flow speeds.