Research on Multiple Bi-Directional DC/DC Converter in Wind Power Flow Optimization and Control System

A kind of multiple bi-directional DC/DC converter used in supercapacitor energy storage unit of the wind power flow optimization and control system is analyzed and studied. Based on DSPs, the converter uses a double closed-loop control strategy to stabilize voltage and uses a digital parallel current sharing strategy to eliminate circulation current among each converter unit. In the paper, firstly, the working principle and the working process of the multiple bi-directional converter are analyzed in detail. Then, on the basis of the small signal model, the way to voltage stabilization and current balance are presented. Finally, a low power converter prototype is designed and made to carry on the experiment. The experimental results show that the proposed control strategies are feasible and effective. So the multiple bi-directional DC/DC converter designed in the paper has comparatively high practicable value in the wind power flow optimization and control system.