Modeling and control of a small marine current power generation system

This paper proposes a simple topological structure and power control method for a small scale stand alone marine current system, in which a diode rectifier, DC/DC boost converter for the maximum power control, battery as a storage element and a single phase inverter to link with load. The paper establishes the steady-state mathematical model of marine current power generation system and derives the formula between the maximum power point and dc battery voltage. Then use the measurements of DC voltage and DC current to obtain maximum power point tracking (MPPT) by controlling the duty cycle of the boost converter switch in order to simplify the system structure and the control strategies. In this case, the hill-climbing searching algorithm is employed to get maximum power point and the double closed loops control strategy is used to improve the dynamic and static performance of single phase inverter. The simulation experiments using Matlab/Simulink and dSPACE hardware-in-the-loop simulation experimental platform demonstrate the feasibility and validity of the proposed control strategies.