Modelling and simulation of a power converter for variable speed hydrokinetic systems

Abstract

This study presents the control scheme model of a micro-hydrokinetic turbine system equipped with a permanent magnet synchronous generator (PMSG). A power conversion system model is developed to allow a variable speed hydrokinetic turbine system to generate constant voltage and frequency at variable water speeds. A DC-DC boosting chopper is used to maintain constant DC link voltage. The DC current is regulated to follow the optimized reference current for maximum power point tracking (MPPT) operation of the turbine system. The DC link voltage is controlled to feed the current into the load through the line-side pulse width modulation (PWM) inverter. The proposed scheme is modelled and simulated using MATLAB/Simulink. The results show a high quality power conversion solution for a variable speed hydrokinetic river system.