A novel control strategy for small wind generation system based on the converter without DC storage components

In small-scale grid-connected wind energy conversion systems with DC-link energy storage components, traditional PWM technology is usually used to produce sine wave output current. However, for the converter topology without DC-link energy storage components used in the wind generation system with a high-inductance permanent magnetic synchronous generator, the DC current in the DC-link of the converter would be fluctuant. In this case, the traditional PWM method can not provide high quality power to the utility. To solve the problem above, a novel control strategy is proposed through detailed analysis of operating characteristics of the system, and an accurate math model of modulation index in accordance with the proposed control scheme is deduced on the basis of energy balance law as well. A simulation model is established for the verification of the proposed method. The simulation results show that the waveform and amplitude of the grid-connected current can be well controlled by the proposed method and control strategy.