A real-time predictive dynamic control strategy for the small wind turbine system based on CSI

For small scale direct drive wind generation systems based on high-inductance permanent magnet synchronous generator (PMSG) and current source inverter (CSI), the combination of PMSG and uncontrolled rectifier forms a DC current source with the inherent fluctuant magnitude because there is no DC inductance to smooth it. Therefore, the exact control of waveform of grid-connected output current of the CSI is impossible just by the traditional SPWM control technology. This paper presents a real-time predictive dynamic control strategy to calculate the factor of amplitude modulation to control both the wave form and the amplitude of output current of CSI fed to the grid. The proposed control strategy is analyzed in detail in theory and validated by simulation and experiment. The simulation results show that by the proposed control strategy, the grid-connected current of CSI can be controlled to follow the reference command exactly and with very low THD. The experiment results will also be given in full paper.